SourceSmall bomb hits NY Times Square
An explosive device has caused minor damage to a military recruitment centre on New York City's Times Square.
The centre was empty and no-one was injured in the pre-dawn blast, which smashed a glass window.
The recruiting station, located on a traffic island, has occasionally been the site of anti-war protests.
A US security official said the possibility of terrorism was being investigated but there was no sign of an immediate threat to the US.
US homeland security department spokesman Laura Keehner said the FBI had joined the investigation.
After the explosion in the early hours of Thursday, police cars blocked surrounding streets.
The traffic island, in the middle of the square, is surrounded by streets, theatres and restaurants. The recruiting station is one of the busiest in the US.
Witnesses staying at a Times Square hotel told the Associated Press news agency that they heard a "big bang" and could feel the building shake.
A plume of smoke was also visible after the explosion, they said.
At one point, subway trains passed through Times Square station without stopping but normal service later resumed.
Good thing no one was hurt.
