The Manhattan blast was caused by a bomb, but early probes have found no link to "international terrorism," New York Governor Andrew Cuomo said. Security forces were on full alert as police searched for suspects.
The FBI was examining the remains of the device used in the Saturday bombing, as well as another explosive device found near the site, New York Governor Andrew Cuomo said on Sunday.
"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," the governor said, referring to the "Islamic State."
At the same time, Cuomo stressed it was "very, very early in the investigation" of the Manhattan blast.
The powerful explosion injured 29 people in the busy neighborhood of Chelsea on Saturday evening. However, only one person suffered serious injuries, according to the police, and all of the wounded have since been released from the hospital.
"When you see the damage, I think we were fortunate that there were no fatalities," Cuomo said on Sunday.
'New Yorkers will not be intimidated'
The improvised explosive device was likely hidden inside a toolbox in front of a construction site, a law enforcement official told the AP news agency. A sweep of the environment discovered an unexploded device four streets away. The homemade bomb consisted of a pressure cooker connected to a cell phone, similar to the device used in the 2013 Boston Marathon attack.
The police managed to defuse and dismantle the bomb. Only hours before the Manhattan blast, a pipe bomb went off in New Jersey, some 130 kilometers (80 miles) from the Chelsea district. The blast caused no injuries.
New York Bill de Blasio said there was no apparent link between the two blasts.
"Now, I want to be clear: Whatever the cause, whatever the intention here, New Yorkers will not be intimidated," he said.
The mayor added that police, law enforcement and the city's "anti-terror capacity in particular" were on full alert.
New York pushes on
An unnamed source told Reuters news agency that "the crudity, positioning, and relative ineffectiveness" of the devices spoke against an involvement by a "sophisticated" terror group.
"We have no reason to believe at this time that there is any further immediate threat," Cuomo said.
"We will find who planted these explosives and they will be punished," he added. "We will not allow these types of people and these types of threats to disrupt our life in New York.
dj/sms (Reuters, AP, AFP)