NEW YORK- Investigators are searching for reasons a Bangladeshi man set off a bomb strapped to his body in a New York City commuter hub during the morning rush hour in what is being characterized as an attempted terrorist attack.

Three people, including a police officer, suffered minor injuries when the suspect, Akayed Ullah, 27, set off a homemade pipe bomb early on Monday in an underground passageway between the subway station underneath the Port Authority Bus Terminal and the Times Square subway station in midtown Manhattan.

Ullah was taken to a hospital after suffering burns from the explosive device, which was attached to his body with Velcro and zip ties and did not fully ignite, officials said.

Investigators told Reuters they believed the attack was intended to be a suicide bombing.

Details of Ullah's background emerged on Monday. The former limousine driver arrived in the United States in 2011 on a family visa, officials said.

Ullah lived with his mother, sister and two brothers in Brooklyn and was a green card holder, said Shameem Ahsan, consul general of Bangladesh in New York.

He came from the southeastern Bangladeshi district of Chittagong and last visited the country on Sept. 8, Inspector General of Police A K M Shahidul Hoque told Reuters on Monday.

Ullah had no criminal record in Bangladesh, Hoque said, and several U.S. officials familiar with the investigation told Reuters there was no information indicating Ullah was previously known to U.S. spy or law enforcement agencies for any connection to militant groups.

Still, authorities are not ruling out the possibility that some connection could be found.

A law enforcement official familiar with the case said investigators had found evidence that he watched the propaganda of Islamic State militants on the internet.

Authorities did not immediately comment on Ullah's motives. Asked whether Ullah had claimed any connection to Islamic State, New York Police Commissioner James O'Neill said: "He did make statements but we're not going to talk about that right now."

The weapon used in Monday's attack was "amateur-level," New York Governor Andrew Cuomo said at a news conference.

Cuomo called the suspect a "lone wolf," similar to the suspect in the most recent attack in New York, when an Uzbek immigrant driving a rented truck mowed down people on a bicycle path on Oct. 31, killing eight.

In recent years, numerous people claiming to be inspired by Islamic State militants have carried out attacks across Europe, the Middle East and the United States.

Officials said the attempted bombing underscored New York City's status as a target for such attacks, citing the attacks of Sept. 11, 2001, which killed more than 2,750 people in New York and nearly 3,000 people in total, and the 1993 World Trade Center bombing, which killed six people.

The blast sent commuters fleeing for the exits and police officers rushing to the scene, as officials scrambled to reroute trains and shut down streets temporarily. (Editing by Bernadette Baum) ((nick.zieminski@thomsonreuters.com; +1 646.223.6162; Reuters Messaging: nick.zieminski.thomsonreuters.com@reuters.net))