A suspicious device found near a New Jersey railway station exploded as a bomb squad was attempting to disarm it with a robot, officials say.
It was one of up to five devices found in a backpack inside a rubbish bin near the station in Elizabeth, according to the city’s mayor. No-one was hurt.
The discovery came after three attacks at the weekend – bombs in New York and New Jersey, and stabbings in Minnesota.
The explosion in New York’s Chelsea area injured 29 people.
In Elizabeth, New Jersey, police detonated a device on Monday following concerns it was a live bomb.
“That was not a controlled explosion,” said Mayor Christian Bollwage, adding that the blast happened as a robot examining a device cut a wire.
FBI Newark said a suspicious package contained “multiple improvised explosive devices”.
It was picked out of a bin by two men who thought the bag could contain something of value.
“They started to examine the backpack when they found the wires and the pipes and they dropped the backpack, walked around the corner, went into police headquarters and notified us right away,” said Mr Bollwage.
In New York City, the FBI said it had stopped a “vehicle of interest” in Brooklyn on Sunday but made no arrests.
Read More: BBC