Explosion at the Manhattan bus terminal

A man is being held after an attempted terror attack at America's biggest and busiest bus terminal, officials say.

"Terrorists won't win. We are New Yorkers," said Mayor Bill De Blasio said after a blast in an underpass at the Port Authority terminal on Monday.

The suspect was wounded. Fire officials say four people were injured, but none is in danger.

US media say the man had a pipe bomb strapped to his body when it detonated at the start of the morning rush hour.

Mr De Blasio said the suspect was believed to have acted alone.

A photo circulating on social media shows a man, said to be the suspect, lying on the ground with his clothes ripped and lacerations on his upper body.

White House press secretary Sarah Sanders said President Donald Trump had been briefed on the incident.

The Port Authority Bus Terminal serves more than 65 million people a year.