BOSTON (CBS) — Police stepped up patrols around major MBTA stations in the city after an explosion at the Port Authority bus terminal in New York City.

At this time, there is no specific threat to Boston, according to officials.

Transit Police at South Station (WBZ-TV)

CBS News reported that early investigations indicate that a possible pipe bomb went off in a subway tunnel close to Times Square around 7:20 a.m. on Monday.

Officials have identified the suspect as 27-year-old Akayed Ullah, a man from Bangladesh living in Brooklyn. He has no criminal history.

Surveillance video appears to show Ullah walking along with commuters in an underground passageway before the explosion.

Ullah, along with three other people, was injured by the explosion of the “crudely-made device,” said CBS New York.

New York City Mayor Bill de Blasio called it “an attempted terrorist attack.”

A law enforcement official says Ullah struggled and it took four Port Authority police officers to wrestle his cell phone away from him. Police are trying to piece together the timeline as they work to learn more about Ullah and his motives.

Boston officials and Mass State Police said they are monitoring the situation and are in contact with New York Police.

WBZ-TV’s Christina Hager reports

Cambridge also tweeted that they would be taking a similar approach.

The MBTA told WBZ-TV, the “Transit Police Department is in communication with its federal, state and local partners particularly the FBI. At this time, Transit Police have no information credible or otherwise to suggest a local threat. Nonetheless, Transit Police will have high visibility coverage at the MBTA’s busiest stations and K9 units deployed throughout the system. If MBTA customers see anything out of the ordinary, they are encouraged to report it to MBTA personnel or Transit Police.”

Former Boston Police Commissioner and WBZ Security Analyst Ed Davis said that all security officials in Boston are well prepared and well trained.

“I know the Transit Police, especially during the holidays, step up their surveillance of what’s happening in the system and so we’re in really good shape here in Boston. The problem is this is a very easy attack to accomplish. And so despite all the intelligence protocols that we have in place, all of the surveillance and the show of force that we use around the holiday season, there can be a problem,” he said.