Mourners gather under an LGBT pride flag flying at half-mast for a candlelight vigil in remembrance for mass shooting victims in Orlando, from San Diego, California, U.S. on June 12, 2016. REUTERS/Mike Blake

UPDATE: 10:06 p.m. EDT — Mourners in Orlando and around the nation and the world paused Sunday night to remember the 50 people killed and the 53 injured in the mass shooting at Pulse nightclub in Orlando, Florida, early Sunday. At Ember in downtown Orlando, crowd members spontaneously broke out into clapping at the close of a twilight candlelight vigil, the Orlando Sentinel reported. At Jones High School, a few miles from Pulse, a vigil organized by the Experience Christian Center brought together seven pastors, “all sharing in prayer, different denominations all coming together for a common cause,” said Experience Senior Pastor Derrick McCrae, the paper reported.

At the start of the live CBS broadcast of the Tony Awards, which honor the best of Broadway, host James Corden gave somber opening remarks addressed to the camera. “All around the world, people are trying to come to terms with the horrific events that took place in Orlando this morning,” he said. “On behalf of the whole theater community and every people in this room, our hearts go out to all of those affected by this atrocity. All we can say is you’re not on your own right now.”

Frank Langella, who won the Tony for Best Actor in a Leading Role in a Play for "The Father," in his acceptance speech said, "I urge you, Orlando, to be strong."

UPDATE: 7:22 p.m. EDT — U.S. Vice President Joe Biden issued a statement Sunday about the mass shooting in Orlando, Florida, calling the killing of 50 people "an act of pure hate and unspeakable terror." He praised the police, first-responders and bystanders who rushed into danger to help victims, saying "their acts are a reminder of the best in our common humanity." He added that he and his wife, Jill Biden, offer their prayers and condolences. "But our prayers are not enough to end these kinds of senseless mass shootings," he said. "The violence is not normal, and the targeting of our lesbian, gay, bisexual, and transgender Americans is evil and abhorrent."

UPDATE: 5:40 p.m. EDT — Donald Trump issued a formal statement on the Pulse nightclub massacre, blaming the mass shooting in Orlando, Florida, on Islamic terrorism.

“If we do not get tough and smart real fast, we are not going to have a country anymore,” Trump said. “Because our leaders are weak, I said this was going to happen — and it is only going to get worse. I am trying to save lives and prevent the next terrorist attack. We can't afford to be politically correct anymore.”

Trump promised to deliver a major speech on the attack Monday, addressing immigration and national security. The speech is set for the Institute of Politics at St. Anselm’s College in New Hampshire at 2:30 p.m. EDT.

UPDATE 4:55 p.m. EDT — New York Gov. Andrew Cuomo urged lawmakers throughout the country to act to create gun legislation to prevent future incidents like the Sunday shooting at a nightclub in Orlando, Florida, that left 50 dead and 53 wounded. Calling the massacre a “horrible reminder” of the necessity for better gun legislation, Cuomo appealed to Congress.

“It is far past time for Washington to act,” he said in a statement.

UPDATE 4:30 p.m. EDT — The city of Orlando, Florida, has begun to release the names of the victims who died at the shooting at Pulse nightclub early Sunday morning. The names posted on the website here are of victims whose identity has been confirmed and whose next of kin has been contacted. The first four people to be identified are Edward Sotomayor Jr., Stanley Almodovar III , Luis Omar Ocasio-Capo and Juan Ramon Guerrero.

UPDATE 3:55 p.m. EDT – The FBI had previously questioned Omar Mateen, the now-deceased suspect in the mass shooting at an Orlando, Florida, gay nightclub that left 50 dead. The agency had interviewed Mateen in 2013 and again in 2014, the latter instance for his possible connections to suicide bomber Moner Abu Salha, releasing him after they found no “substantial relationship” between the two men.

Mateen had legally purchased two weapons in the past week, a spokesperson from the Bureau of Alcohol, Tobacco, Firearms and Explosives said in the same news conference. He reportedly used an AR-15-style assault rifle when he opened fire on clubgoers Sunday morning around 2 a.m.

UPDATE 3:20 p.m. EDT – Leaders throughout the state of Florida and throughout the country offered their support to the victims of a mass shooting at a club in Orlando, encouraging people to comfort and love one another. Florida Gov. Rick Scott called for everyone in the nation to observe a moment of silence at 6 p.m. EDT Sunday to memorialize the victims of an attack that left 50 dead and 53 wounded.

“We need to support each other, we need to love each other and we will not be defined by a hateful shooter,” Mayor John Hugh "Buddy" Dyer said.

The remaining three presidential candidates, Democratic hopefuls Hillary Clinton and Bernie Sanders, as well as Republican Donald Trump, made public statements on their social media accounts. All three condemned the attack, with Trump congratulating himself on Twitter for “being right on Islamic terrorism.”

UPDATE 2:45 p.m. EDT – The terror organization known as the Islamic State group, or ISIS, claimed responsibility for a mass shooting in a gay nightclub around 2 a.m. Sunday morning in Orlando, Florida, Reuters reported. At least 50 people were killed in what President Barack Obama called the deadliest mass shooting on U.S. soil.

"The armed attack that targeted a gay night club in the city of Orlando in the American state of Florida which left over 100 people dead or injured was carried out by an Islamic State fighter," Amaq, the Islamic State group’s news organization reported.

UPDATE 2:21 p.m. EDT – The ex-wife of Omar Mateen, the reported gunman of a mass shooting at a gay nightclub Sunday morning, said she had left her former husband for beating her and for being mentally unstable. His ex-wife spoke to the Washington Post on the condition of anonymity, describing Mateen as a violent man who was not very religious.

“He was not a stable person,” Mateen’s ex-wife told the Post. “He beat me. He would just come home and start beating me up because the laundry wasn’t finished or something like that.”

UPDATE: 2:02 p.m. EDT — President Barack Obama addressed the country in a news conference Sunday afternoon, condemning the massacre early Sunday morning that left 50 people dead in a nightclub in Orlando, Florida. Obama expressed his condolences while reminding the country of how easy it is for someone to purchase an assault weapon in the U.S.

“Today as Americans we grieve the brutal murder and horrific massacre of dozens of innocent people,” he said, adding, “We know enough to say that this was an act of terror and an act of hate.”

Pope Francis, leader of the Roman Catholic Church, added his condolences to the victims and their families, calling the incident “senseless hatred,” Agence-France Presse reported.

UPDATE 1:36 p.m. EDT — Law enforcement agencies say reported gunman Omar Mateen pledged his allegiance to the terror organization known as the Islamic State group in a 911 call before he opened fire on a gay nightclub early Sunday, NBC News reported. At least 50 people died and 53 more were wounded in an attack that was the worst mass shooting on U.S. soil.

UPDATE: 1:01 p.m. EDT — Presidential candidate and Vermont Sen. Bernie Sanders condemned Sunday’s attack on a Florida nightclub, saying that comprehensive gun reform was needed to stop future attacks from happening.

“We should not be selling automatic weapons which are designed to kill people. We have got to do everything that we can on top of that to make sure that guns do not fall into the hands of people who should not have them, criminals, people who are mentally ill,” he told NBC News.

UPDATE: 12:45 p.m. EDT — The local Florida chapter of the Council on American-Islamic Relations has begun soliciting blood donations for victims of a shooting at Pulse nightclub in Orlando, Florida, Sunday. The organization offered their condolences to victims and their families after authorities revealed the reported shooter may have had connections to Islamic extremist groups.

“The Muslim community joins our fellow Americans in repudiating anyone or any group that would claim to justify or excuse such an appalling act of violence,” the group said in a statement.

UPDATE: 12:30 p.m. EDT — Florida Gov. Rick Scott declared a state of emergency following a massacre at an Orlando nightclub that left 50 dead early Sunday morning. News of the state of emergency came as reports surfaced that law enforcement had suspected shooter Omar Mateen on their radar for at least the past five years, CBS News reported.

“We will come together and do everything we can for everyone who was impacted," Scott said, adding, “It’s devastating. You don’t want this to happen anywhere in the world.”

UPDATE: 12:16 p.m. EDT — The Tony Awards will dedicate Sunday evening’s show to the victims of the mass shooting at Pulse nightclub in Orlando, Florida, according to a Tweet posted from the verified account of the awards show. At least 50 people were killed after a gunman opened fire on the popular gay club early Sunday morning, and the investigation is ongoing.

UPDATE: 12:00 p.m. EDT — Two members of Congress linked the alleged shooter in Sunday’s Orlando, Florida, gay nightclub shooting to Islamic radicalism. Rep. Peter King, R-N.Y., told CNN his sources confirmed the gunman, identified as Omar Mateen of Port St. Lucie, had ties overseas and Sen. Bill Nelson, D-Fla., tweeted the shooter had a “connection to ISIS.”

UPDATE: 11:41 a.m. EDT – A Kevlar helmet may have saved the life of an Orlando police officer who was struck during the rescue mission at Pulse nightclub early Sunday morning, according to a tweet posted to the Orlando Police Department’s verified Twitter account. The helmet deflected a bullet during the raid that saved the lives of at least 30 people.

UPDATE: 11:27 a.m. EDT – The weapon used to kill 50 people and wound at least 53 more in a nightclub in Florida Sunday was an AR-15-style, similar to the rifle used in the Sandy Hook massacre that left 26 dead at an elementary school in Connecticut in 2012. The gunman who attacked the Pulse nightclub had been armed with a AR-15-style rifle and a handgun, according to Orlando Police Department Chief John Mina.

UPDATE: 11:15 a.m. EDT – The father of reported gunman Omar Mateen, who killed 50 people in a gay nightclub in Orlando, Florida, apologized for his son’s actions Sunday. Mateen’s father Mir Seddique said the incident had nothing to do with religion and may have been a result of deep anger his son felt after seeing two gay men kissing several months earlier.

"We are saying we are apologizing for the whole incident. We weren't aware of any action he is taking. We are in shock like the whole country," Seddique told NBC News.

UPDATE: 10:59 a.m. EDT – The gunman who killed 50 people and wounded at least 53 more in a gay nightclub early Sunday morning received training from terrorists in Afghanistan, New York Republican Rep. Peter King said Sunday morning. The deceased assailant has been identified as Florida resident and U.S. citizen Omar Mateen, aged 29.

"He was from Afghanistan and was trained in the use of weapons — that's as far as I'll go," King told CNN Sunday.

UPDATE: 10:36 a.m. EDT – The FBI are in the process of notifying families who lost loved ones in a shooting in a gay nightclub in Orlando, Florida early Sunday in what authorities are calling one of the worst mass shootings in U.S. history. The agency has also encouraged everyone who attended Pulse nightclub at any point Saturday to come forward with any information they may have.

Local religious and political leaders joined in the mourning of the dead, as Imam Muhammad Musri, leader of the Islamic Society of Central Florida, called on the media not to politicize the night's event.

"I'm here today to stand as a faith leader with our law enforcement community and city leadership," Musri said, adding, "I want to caution many in the media from rushing to judgment."

UPDATE: 10:23 a.m. EDT – At least 50 people were killed in the shooting in a nightclub in Orlando early Sunday morning, up from a previously estimated 20 casualties, Mayor Buddy Dwyer said at a news conference Sunday. There were at least 53 people wounded in the same incident.

Original Story:

Authorities in Orlando, Florida, were investigating domestic terror as a possible motive behind a shooting that left 20 dead and at least 42 wounded at a gay nightclub early Sunday. Police are still looking at all possible motives but said there was evidence the shooter had ties to some Islamic extremist groups.

"We do have suggestions that that individual may have leanings toward that, that particular ideology. But right now, we can’t say definitively, so we’re still running everything around,” said Ron Hopper, FBI assistant agent and head of the Tampa division, at a Sunday press conference.

The assailant opened fire on the nightclub around 2 a.m. Sunday, reportedly using an assault rifle and a handgun to kill 20 people. He may have had some kind of explosive device strapped to him, according to police.

After the attacker took hostages, law enforcement used explosives and an armored car to break down a wall and enter the nightclub, killing the attacker in a shootout. Police have now identified the deceased suspect as Omar Mateen, CBS News reported. Mateen was approximately 30 years old, a U.S. citizen born to Afghan parents in neighboring Port St. Lucie, Florida. He appears to have acted alone.

The Orlando community mourned for the loss of life Sunday morning; notably, the shooting came as gay pride week festivities were in full swing. The club had been a treasured spot, and its owner opened it to raise awareness about issues in the gay and lesbian community after her brother John died of AIDS.

"It was important to create an atmosphere that embraced the gay lifestyle with décor that would make John proud. Most importantly, [we] coined the name Pulse for John’s heartbeat — as a club that is John’s inspiration, where he is kept alive in the eyes of his friends and family," reads a description from the club’s website.

President Barack Obama has now been briefed on the news, and likely presidential nominees Republican Donald Trump and Democrat Hillary Clinton reacted to the night's events in posts to Twitter Sunday morning, expressing their concern for the situation.