Iraqis gather at the site of an attack in eastern Baghdad on Jan. 11, 2016. Islamic State group claimed responsibility for an attack in eastern Baghdad that killed at least 12 people. SABAH ARAR/AFP/Getty Images

UPDATE: 1:22 p.m. EDT — At least six men exploded a car bomb and tried to hold more than 50 hostages Monday at a mall in eastern Baghdad, the Iraqi government said. Security forces killed four of the attackers, while two killed themselves with a suicide vest that targeted civilians.

Iraqi forces landed on the roof of the mall after the gunmen entered the shopping complex and fought off the attackers, the Associated Press reported. The city's highly fortified Green Zone, where many foreign embassies and most of the country's political elite are located, was closed down after the attack.

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UPDATE: 12:55 p.m. EDT — The Islamic State group has claimed responsibility for a mass shooting Monday at a mall in eastern Baghdad. ISIS claimed four of its fighters had attacked a gathering of "rejectionist heathens," the group's derogatory term for Shiite Muslims. At least 18 people died, Reuters reported.

UPDATE: 12:30 p.m. EDT — At least 12 people were killed Monday during a terrorist attack targeting a shopping mall in Baghdad. Security officials said the attack was over a few hours after it began, around 5:30 p.m. local time. The cause of the attack and the identities of the dead remained unknown.

UPDATE: 11:55 a.m. EDT — An attack involving hostages at a Baghdad mall began Monday after two men detonated a parked car outside the shopping center, a Wall Street Journal reported said. The men opened fire on the crowd outside the mall before donating their suicide vests. Matt Bradley, a Wall Street Journal reporter focusing on Iraq, said attacks like the one Monday at the Al Jawhara Mall are rare.

"They are inside the Zahrat Baghdad mall. When the security forces got too close, they killed three hostages," a police official told NDTV. "We are taking a cautious approach now. We want this attack to end with the lowest possible number of casualties.”

The gunmen also gathered at one point on the roof of the mall. Security officials had reportedly killed at least some of the gunmen, but it was unclear if all the attackers had been killed and all the hostages had been freed.

UPDATE: 11:30 a.m. EDT — Security officials have reportedly killed a group of militants who stormed a Baghdad shopping mall Monday, killing eight people, including a child, and injuring more 25. The men began the attack after a nearby car bomb went off. It was not immediately clear if the attacks were coordinated.

Amateur video of the attack was published on Twitter by social media users, but it was unclear if the video was authentic. The graphic video is below:

UPDATE: 11:25 a.m. EDT — More than 50 people were trapped in mall in eastern Baghdad Monday after gunmen stormed the area and claimed hostages. Officials said at least 25 people were wounded, the Associated Press reported. The men stormed the complex after a car bomb exploded outside in the predominately Shi'ite Muslim district of Baghdad Jadida.

The Islamic State group could be behind the attack, according to a report from the Levantine Group, an independent research and risk assessment consultancy firm. "The modus operandi of the attack, that is, bombings followed by gunmen indicates that ISIS is likely responsible for the attack. In this context, with the group losing territory in areas of Iraq, most recently in Ramadi, ISIS is likely attempting to demonstrate its continued capabilities while also encouraging deployments away from active battle fronts," the report said.

Original story:

At least 27 people were wounded in the bomb blast, the Jerusalem Post reported. Security forces immediately called the bombing a terrorist attack but it was unclear who was responsible. Some reported indicated at least 20 men were involved in the attack. The Associated Press reported 10 people had been killed.

Streets near the shopping mall were shut down, the BBC reported. Three police officers were reportedly among the dead.

Baghdad has been the site of a various bombings carried out by the Islamic State group in recent months as ISIS has targeted the country’s Shiite majority. A car bomb attack in the Ameen district of eastern Baghdad killed at least 17 people in September. Last week, three Sunni mosques in Iraq were bombed and partially destroyed in suspected retaliation for the execution of a Shia leader in Saudi Arabia. Most recently, three people were killed and eight others wounded when a car bomb went off early Monday near a restaurant in Baquba, about 40 miles northeast of Baghdad, security and medical sources said. ISIS claimed responsibility for the bombing.

This is a developing story.