An bomb found near a train station in Elizabeth, New Jersey, exploded early Monday morning while it was being investigated by a robot, the city’s mayor told NBC News. No one was injured in the blast, which officials at first referred to as a “controlled explosion.”

Videos from the scene shows the moment of the blast (warning — language):

WATCH: Explosive device detonates near Elizabeth train station as robot was examining it pic.twitter.com/OQp2xr0aNl — Jessica Remo (@JessicaRemoNJ) September 19, 2016

#BREAKING video shows moment bomb robot accidentally detonated device found @ Elizabeth NJ train station. @PIX11News pic.twitter.com/xfO97F2ebm — Anthony DiLorenzo (@ADiLorenzoTV) September 19, 2016

BREAKING PHOTO: blast near Elizabeth NJ train station as bomb techs try to disarm device. Video soon. @PIX11News pic.twitter.com/doX6PgktXw — Anthony DiLorenzo (@ADiLorenzoTV) September 19, 2016

“Mayor of Elizabeth, NJ now says this was NOT a controlled explosion. Says this “was an explosive device” and “could have hurt a lot of ppl,” NBC’s Miguel Almaguer said on Twitter. “Elizabeth, NJ mayor says 5 devices were left in a single backpack. Had “bomb” went of “it would have certainly killed/injured many”.

Thunderous explosion that seemed to startle many police + sent others running heard in Elizabeth, NJ train station pic.twitter.com/o0ilhsY7BW — Miguel Almaguer (@Miguelnbc) September 19, 2016

NBC News' @Miguelnbc reports that a robot was attempting to cut in the device in New Jersey when the device exploded. — Tom Winter (@Tom_Winter) September 19, 2016

The NJ Transit station was evacuated and the surrounding area shut down after the “suspicious package,” was found Sunday night, NBC News’ Tom Winter reports.

NBC NEWS: Significant law enforcement presence at the New Jersey Transit stop in Elizabeth, NJ for a suspicious package. Service suspended. — Tom Winter (@Tom_Winter) September 19, 2016

BREAKING: Trains stopped near NJ Transit station in Elizabeth for a suspicious package. Officials say they are taking this very seriously. — Tom Winter (@Tom_Winter) September 19, 2016

The New York Daily News reports that three pipe bombs and two smaller devices were found at the Elizabeth train station.

Suspicious Device Found in ElizabethSuspicious Device 2016-09-19T02:30:53.000Z

The city’s mayor, J. Christian Bollwage, spoke to reporters at the scene, saying the suspicious devices were found about 9:30 p.m. on Broad Street and Julian Place, near the train station. The package was found in a “waste basket” by two men, Bollwage said.

“They took the package out of the waste basket because they thought it might be of some value to them,” Bollwage said. “(They) walked under the arch, or the railroad trestle, around the corner near an SUV, saw wires and a pipe, dropped the package, thought it was no good, went to police headquarters to notify the Elizabeth Police of what they just found.”

Bollwage said officers responded and found the package and “thought it could be a bomb.”

The county bomb squad was brought in, which sent a “drone” to investigate further, the mayor said. The drone indicated it “could be a live bomb.”

The FBI and State Police are investigating.

There is no threat to public safety as the package is being secured and investigated. — Chris Bollwage (@MayorBollwage) September 19, 2016

“Currently all trains, both New Jersey Transit and Amtrak, are shut down going through the Elizabeth station,” Bollwage said.

A secondary search for other trash cans is being conducted.

You can watch video of Bollwage’s press conference below:

Elizabeth Mayor Speaks on Suspicious Device FoundSuspicious Device 2016-09-19T03:21:13.000Z

The incident comes after bombs were detonated in Seaside Park, New Jersey, Saturday morning and in the Chelsea neighborhood of New York City later that night. No one was injured in the Seaside Park incident, while 29 people were hurt, one seriously, in the Chelsea blast.

Both of those bombs were planted in trash cans. NBC News reports the Elizabeth device is similar to the one used in Seaside Park:

NBC NEWS: Device found in Elizabeth at a NJ Transit stop is similar in appearance to device found in Seaside Park, NJ. FBI investigating. — Tom Winter (@Tom_Winter) September 19, 2016

Winter reported on Twitter that law enforcement officials are concerned there “MAY be an active terror cell” in the New York and New Jersey area.

NBC News: Law enforcement officials say that they are concerned that there MAY be an active terror cell in the NY/NJ area w/ @jonathan4ny — Tom Winter (@Tom_Winter) September 19, 2016

Authorities are working to determine if the Seaside Park and Chelsea blasts are connected. Law enforcement sources told CNN the devices were similar. The devices in both locations used cell phones as timers, CNN reports.

Officials told the Associated Press that residue from Tannerite, an explosive power, was found at the Chelsea explosion.

The Elizabeth device was also found about the same time the FBI detained five people on the Belt Parkway near the Verrazano Bridge in New York as part of the investigation, according to CBS New York.

Suspicious Device Near Elizabeth train stationSuspicious device 2016-09-19T02:42:45.000Z

New Jersey Transit said on Twitter that trains are being stopped along the Northeast Corridor.

#NEC rail service is temporarily suspended between Newark Airport and Elizabeth stations due to police activity near Elizabeth. — NJ TRANSIT (@NJTRANSIT) September 19, 2016

Some Twitter users reported being stuck on trains for more than 45 minutes during the investigation:

We're sitting at Elizabeth NJ @NJTRANSIT stop for 45 min so far due to police activity… ?? https://t.co/Kaq8IduzFt — Saleem (@smalkana) September 19, 2016