Manchester Arena bombing
Police are seen outside the Manchester Arena in northern England where singer Ariana Grande had been performing in Manchester, Britain, May 22, 2017. Reuters/Jon Super

UPDATE: 7:51 a.m. EDT — The Islamic State group on Tuesday claimed responsibility for the attack at the Manchester Arena in northern England Monday night that left at least 22 people dead, saying that one of its members was behind the bombing.

Original Story:

Supporters of the Islamic State group (ISIS) celebrated on social media Tuesday after the blast in Manchester Arena, in the north of England, that killed at least 22 people and wounded more than 50 others. Although the Islamist group has not taken responsibility for the attack, Twitter accounts affiliated with the terrorist organization sent out celebratory messages.

The attack, which took place late Monday night as nearly 21,000 people were leaving a concert by singer Ariana Grande, was in some messages described as an act of revenge in response to air strikes in Iraq and Syria. "It seems that bombs of the British airforce over children of Mosul and Raqqa have just come back to #Manchester," one user named Abdul Haqq said on Twitter, in reference to the Iraqi and Syrian cities held by the militants where a U.S.-led coalition, of which Britain is a member, is conducting airstrikes.

Read: What Happened At Ariana Grande Concert? Suicide Bomber Suspected For Explosion

Apart from celebratory messages, other messages that went out with the hashtags referring to the blast, encouraged more "lone wolf" attacks. The messages also contained ISIS videos threatening the United States and Europe. Some other users posted banners that read: "the beginning is in Brussels and Paris, and in London, we form a state," in reference to previous similar "lone wolf" attacks in Belgium and France for which the terror group has claimed responsibility.

Meanwhile, another user said on a channel affiliated to the group hosted by messaging network Telegram: "We hope that the perpetrator is one of the soldiers of the caliphate."

British police said late Monday that the attack was being treated as a "terrorist incident" and an investigation is underway.

“The injured are being treated at six hospitals across Greater Manchester. My thoughts are with all those who have been affected and we are doing all we can to support them,” Chief Constable Ian Hopkins said in a statement.

British Prime Minister Theresa May responded to the attack, saying her thoughts are with victims and families of what police have described “as an appalling terrorist attack.”

Grande, who was performing at the event was unharmed. She broke her silence over the attack after police confirmed the number of deaths and injuries. “Broken. From the bottom of my heart, I am so so sorry. I don’t have words,” Grande tweeted.

The “Side to Side” singer's management team also issued a statement to Billboard, calling the incident a "senseless attack." The 23-year-old was scheduled to perform Thursday and Friday at the O2 Arena in London before moving on to Belgium, Poland, Germany, Switzerland, and France for other performances.

"Tonight, our hearts are broken," the statement read. "Words cannot express our sorrow for the victims and families harmed in this senseless attack. We mourn the lives of children and loved ones taken by this cowardly act," the statement continues. "We are thankful for the selfless service tonight of Manchester's first responders who rushed towards danger to help save lives. We ask all of you to hold the victims, their families, and all those affected in your hearts and prayers," it added.