New York explosion injures 25 people on Saturday - police

An explosion that shook New York's crowded Chelsea neighborhood injured 25 people, firefighters said Saturday.

"25 injuries to civilians confirmed at 133 W 23 St in Chelsea. None appear to be life-threatening at this time," the Fire Department NY tweeted.

"Explosion happened at roughly 8:30pm (0030 GMT Sunday) on 23rd street between 6th and 7th avenues," in Manhattan, spokesman J. Peter Donald tweeted. "Several injured transported to area hospitals."

The cause of the blast remains unknown, but some local media and social media reports said it appeared to come from a dumpster.

The fire department was at the site of the blast, an area of many restaurants, bars, theatres and apartments. The New York police counterterrorism unit were also on site, and police blocked off the area around the scene.

The blast comes after a pipe bomb exploded in a garbage can in Seaside Park, New Jersey during a Marine Corps charity run. It caused no injuries but forced officials to cancel the event.

The New Jersey explosion was set for the moment that thousands of runners would be passing the can - but there were no casualties because the race was delayed, said Al Della Fave, a spokesman for the Ocean County prosecutor.

There were up to four timed explosives but only one detonated, Fave told CNN.