A Brooklyn man wearing a pipe bomb attached with Velcro and zip ties set off an explosive in the Times Square subway station Monday morning, injuring himself and three others, sending ambulances racing and commuters fleeing as Christmas shoppers poured into New York City. He later said he is a follower of Islamic State.

The 27-year-old suspect, Akayed Ullah, wore the device that went off shortly after 7 a.m. in an attempted terror attack, Police Commissioner James O'Neill said at a news conference near the scene. Ullah suffered serious burns, while other victims had minor injuries, he said.

The suspect came to the U.S. from Bangladesh in 2011 on a family immigrant visa and is a legal resident, Department of Homeland Security spokesman Tyler Q. Houlton said on Twitter. Ullah lives on Ocean Parkway in Brooklyn with his mother and a sister, according to a police official knowledgeable about the investigation. He worked as a driver, but has a background as an electrician.