There was a suspicious package with multiple improvised explosive devices this evening at the Elizabeth Train Station in NJ. #Elizabeth— FBI Newark (@FBINewark) September 19, 2016
No one was injured in the blast that followed a series of attacks in the United States over the weekend, including a Saturday night bombing that hurt 29 people in Manhattan.
The device in Elizabeth, a city south of Newark, had been left in a backpack placed in a trash can near a train station and a bar, Mayor Christian Bollwage told reporters.
As many as five potential explosive devices tumbled out of the backpack when it was emptied, Bollwage said. After cordoning off the area, a bomb squad used a robot to cut a wire to try to disable the device, but inadvertently set off an explosion, he said.
"I can imagine that if all five of them went off at the same time, that the loss of life could have been enormous if there was an event going on," Bollwage said.
Bollwage said it was unclear whether Elizabeth, a city with a population of nearly 130,000 people that is less than 15 miles (24 km) southwest of Manhattan, was specifically targeted or if the backpack might have been discarded to elude investigators.
Authorities early on Monday were seeking to remove the other devices found in the backpack, Bollwage said.
Late on Saturday, a powerful explosion rocked Manhattan's popular Chelsea neighborhood when a pressure-cooker bomb packed with shrapnel detonated. A similar unexploded device was found a few blocks away later that night.
The Chelsea blast followed a pipe bomb explosion on Saturday morning along the route of a running race in the New Jersey beach town of Seaside Park. No one was injured in that blast.
An FBI spokesman in Newark, Mike Whitaker, said agents were aware of the situation in Elizabeth. "We are responding with our local law enforcement partners," he added, but declined to give further details.
The backpack in Elizabeth was discovered on Sunday evening by two men scavenging trash, Bollwage said.
They reported the package to police after they "saw wires and a pipe," he added.