Police stand guard at a street near the United Nations headquarters in New York, the United States on Sept 19, 2016. Security has been enforced in New York as a series of high level meetings are held at the UN Headquarters since Monday. [Photo/Xinhua]

Rahami should be considered "armed and dangerous," New York City Mayor Bill de Blasio said in one of a series of TV appearances minutes after the release of the photo.

Early Monday, FBI agents flocked to an apartment above a fried chicken restaurant in Elizabeth that the authorities said was tied to Rahami.

Just hours earlier, one of the five explosive devices discovered Sunday night at the nearby Elizabeth train station exploded when investigators were trying to defuse it with a robot.

Rahami, whose fingerprint was found on an unexploded device, was manhunted in connection with the blasts that provoked suspicions of a local terror cell, according to federal officials.

In addition to the Chelsea blast on Saturday night, another unexploded device apparently made out of a pressure cooker was found several blocks away.

On the immediate heels of the blast, both New York city mayor de Blasio and New York Governor Andrew Cuomo were cautious about linking the attacks to international terrorism.

However, both struck a different tone on Monday morning.

"I suspect there may be a foreign connection," Cuomo told CBS News. "That's what we are hearing today, as the investigation goes on."

On Saturday, a pipe bomb exploded in a garbage pail along the route of a five-km charity run sponsored by the US Marine in New Jersey's Seaside Park, the Ocean County, about 129 km south of New York City.

The explosive device went off before the road run, thus inflicting no injuries or damages, according to local authorities.

Also on Saturday, a man stabbed and injured nine people at a mall in the northern U.S. state of Minnesota before a police officer fatally shot him.