New York, Dec 11 (Agencies): There have been reports of an explosion at a bus terminal in Manhattan and the New York City Police said they were responding to it.

The New York Police Department was responding to reports of an explosion of unknown origin on Monday morning in midtown Manhattan at 42nd Street and 8th Avenue, according to the police department's official Twitter feed.

Some subway train lines there were being evacuated.

The New York fire department said it was responding to an incident at the Port Authority bus terminal in midtown Manhattan.

NYDP said they were investigating an explosion of "unknown origin" in Manhattan, and that people were being evacuated.

"The NYPD is responding to reports of an explosion of unknown origin at 42nd Street and 8th Ave, #Manhattan. The A, C and E line are being evacuated at this time. Info is preliminary, more when available," the New York police department wrote on their Twitter account.

Authorities are urging commuters to avoid the area near Port Authority due to police activity, NBC New York reported.

Pipe bomb detonation in a passageway below ground at Port Authority is being considered a possibility. One person is in custody. Some people have been injured. Police have obtained video and are confident it is under control, ABC News reported.