As the investigation continued into the blast that injured 29 people in New York City’s Chelsea neighborhood on Saturday night, the FBI questioned five people early Monday following a car stop in Brooklyn.

Bureau investigators stopped the car, which an FBI spokeswoman referred to as a “vehicle of interest in the investigation,” on Sunday night, the Associated Press reports. The five people were taken to an FBI building in lower Manhattan to be questioned, according to sources who spoke to the AP.

See also: What to Know About the Chelsea Explosion

Also on Sunday, two men reported seeing a suspicious backpack in a trash can near the Elizabeth train station on the NJ Transit/Amtrak Northeast Corridor line. The men saw wires and a pipe coming out of the bag on top of a municipal garbage can as they came out of a nearby restaurant, Elizabeth Mayor Christian Bollwage said, reports The New York Times.

One of the five bombs found in the bag exploded when police tried to disarm it with a robot around 12:30 a.m. Monday morning, but no injuries were reported.

The discovery of the devices and the subsequent explosion led to a suspension of train service on the busy Northeast Corridor line. “Northeast Corridor and North Jersey Coastline rail service is suspended due to police activity in Elizabeth,” NJ Transit said in a posting on its site. The NJ Transit’s Northeast Corridor service has a weekday ridership of more than 115,000.

Passengers on trains reported being stuck onboard stopped carriages for hours on Sunday night, with several being reversed to nearby stations to allow passengers off.

The devices found in Elizabeth come on the heels of the Chelsea bombing—where authorities said they believed a homemade bomb had been placed under a dumpster several blocks away from an unexploded pressure cooker device—as well as the explosion of a pipe bomb in Seaside Park, N.J., about 65 miles south of Elizabeth, which led to the cancellation of a military charity 5-kilometer race.

 

This story will be updated as events develop.