WATCH: Bomb Explodes at Elizabeth, New Jersey, Train Station

The scene in Elizabeth, New Jersey. (@MayorBollage/Twitter)

The scene in Elizabeth, New Jersey. (@MayorBollage/Twitter)

An explosion rocked the New Jersey city of Elizabeth early Monday morning as a robot investigated a suspicious package near a train station, officials say.

While no one as injured, the explosion was not a controlled detonation, the city’s mayor, Christian Bollwage, told NBC News. He said the suspicious package contained “an explosive device” taht “could have hurt a lot of people,” adding that there were five devices inside a single backpack that “would have certainly killed” and injured “many.”

You can watch video of the moment the device exploded below:

Another video shows reporters and others at the scene reacting to the blast (warning — language):

The blast came came a little more than 24 hours after 29 people were wounded, one seriously, in an explosion in the Chelsea neighborhood of New York City. That Saturday night blast was caused by explosives left in a trash dumpster.

The Elizabeth device was also found a day after a bomb exploded near the starting line of a military charity race in Seaside Park, New Jersey. Police and federal authorities are investigating whether the three incidents, along with another suspicious device found in New York City, are connected. Five people were detained by the FBI after a traffic stop in New York as part of the investigation, but no arrests have been made.

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

The city’s mayor, 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.

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.

Trains into and out of the station were stopped Sunday night as a result of the investigation.

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

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.

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.