A 911 caller warned of further explosions after the dumpster blast that hit New York, wounding 29 people, as the governor declared the attack an act of terrorism.
Law enforcement sources told The New York Post an unidentified man called police, claiming to be standing at 23rd Street and Seventh Avenue in the aftermath of the blast.
“I’m looking at the explosion down the block. There will be more,” he reportedly said.
The news comes as New York Governor Andrew Cuomo called the Chelsea explosion “an act of terrorism”, but said there was “no evidence” of ties to an international group.
The bombing is one of three “terror attacks” on US soil in one day, including a mass stabbing at a Minnesota shopping centre claimed by Islamic State and a pipe bomb explosion in New Jersey ahead of a charity race.
New York City police say they’re going to blow up the second device found blocks away from where a bomb exploded in Manhattan on Saturday night.
The controlled detonation will take place at a police facility in the Bronx on Sunday evening.
The second device was described by a law enforcement official as a pressure cooker with wires and a cellphone attached to it. It was taken from the scene by a bomb removal robot.
Authorities have discovered the explosive contained Tannerite, an explosive often used in target practice that can be picked up in many sporting goods stores.
A law enforcement source has told Fox News the New York and New Jersey explosive devices are from the “same person”.
Police are still investigating the incidents but have not ruled out a possible bombing link.
‘TERROR’ IN CHELSEA
The bomb exploded in the street outside the Townhouse Inn of Chelsea, one of the most fashionable districts of Manhattan, at around 8.30pm Saturday (10.30am Sunday AEST).
A second device that failed to detonate, believed to be a pressure cooker, was found four blocks away, police said.
CCTV footage captured the moment the blast ripped through Chelsea, causing panicked pedestrians to run for their lives.
The video, supplied by OrangeTheory Fitness Chelsea, showed a large flash appear in the road, before passersby began to run.
“A bomb exploding in New York is obviously an act of terrorism, but it’s not linked to international terrorism. In other words, we find no ISIS connection, et cetera,” said Cuomo in reference to the Islamic State extremist group based in Iraq and Syria.
“But a bomb going off is generically a terrorist activity. That’s how we’ll consider it. And that’s how we will prosecute it,” he added.
The governor stressed that while there was no evidence of an international terror connection “at this time,” it was still “very early in the investigation.”
Mayor Bill de Blasio refused to be describe the attack as terrorism.
“It was intentional, it was a violent act, it was a bomb. That’s what we know,” he said.
All 29 of the injured have since been released from the hospital.