SOUTH PLAINFIELD — A borough man was arrested and charged with possession of a "destructive device for an unlawful purpose" Monday -- part of an incident that prompted Monday's cancellation of the community's long-running Labor Day festivities.

Gov. Phil Murphy had been expected to attend the labor day parade, but all activities were canceled amid the discovery of what multiple publications, citing unnamed police sources, described as explosives of some kind.

Thomas G. Kaiser, 55, was arrested and charged with one count of possession of a destructive device for an unlawful purpose in the second degree and one count of possession of a destructive device in the third degree, according to the Middlesex County Prosecutor's Office.

Police expected that additional charges will be forthcoming, Middlesex County Prosecutor Andrew Carey's office said.

South Plainfield Police canceled the South Plainfield Labor Day Parade "out of an abundance of caution and due to the potential threat to the community," Carey's office also said.

Carey's office said the investigation began in Monmouth County on Sunday, Sept. 1, when a suspicious package with a destructive device was left at Donovan’s Reef in Sea Bright.

An investigation by Sea Bright police and the Monmouth County Prosecutor’s Office led to Kaiser's South Plainfield residence, which is near the start of the South Plainfield Labor Day parade, Carey's office said.

Investigating officers found other destructive devices near his home, which is located in the vicinity of the start of the South Plainfield Labor Day Parade prompting its cancellation, Carey said.

While police did not publicly disclose the home's location, public records show a W. Crescent Parkway address for Kaiser.

South Plainfield Mayor Matthew Anesh said in a Monday news conference from town hall that Kaiser was arrested a little before midnight, Sunday into Monday morning.

TAPinto South Plainfield live streamed the conference, during which Anesh said a number of devices were found near Kaiser's home and near the start of the parade, which Anesh said he believed had not been cancelled before in its decades-long run.

Anesh said the devices were of a homemade nature and were not remote controlled, but declined further comment when asked about the suspect's brother telling some reporters that the devices were "just fireworks."

He also repeated there was no indication that the devices were "planted" but were found in the vicinity of Kaiser's house.

The Middlesex County Prosecutor's Office did not immediately respond to a request for further description of the destructive devices that were recovered.

Kaiser was taken to the Sea Bright Police Department where he was criminally charged.

Carey also said "If anyone sees or uncovers a suspicious package, they are urged to contact law enforcement."

Also credited with assisting the investigation were the state Office of Homeland Security and Preparedness, the FBI, the State Police Bomb Squad and various K-9 units.

Anyone with relevant information is asked to contact Sea Bright Police at 732-842-0010, the Monmouth County Prosecutor’s Office at 732-803-5406, or South Plainfield Police at 908-755-0700.

"NJOHSP cannot comment on an active or ongoing investigation. We continue to work with our local, county, State, and federal law enforcement partners," a spokesman for the state Office of Homeland Security and Preparedness said to NJ 101.5 News in a written response.

A report by ABC Eyewitness News, cited police as describing the devices as "firework-like devices." NJ.com cited an unnamed official from the state's homeland security office describing the devices as "pipe bomb-like" explosives. New Jersey 101.5 has not yet independently confirmed either description.

TAP into South Plainfield reported a large police presence around the planned start of the 62nd annual parade at the PAL building.

Correction: A previous version of the headline on this story incorrectly described the devices as in South River.

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