A Mason, Ohio, man was arrested for allegedly possessing a destructive device after an investigation into an improvised explosive device (IED) found at a soccer complex led to the discovery of bomb-making materials.

James River Phillips, 20, was arrested Thursday by the FBI Cincinnati Field Office’s Joint Terrorism Task Force and charged with possession of an unregistered gun and possession of a destructive device.

The arrest comes after the task force conducted a federal court-ordered search in Mason that morning.

“The FBI’s Joint Terrorism Task Force arrested James River Phillips after he allegedly possessed a dangerous destructive device,” FBI Cincinnati Special Agent in Charge Elena Iatarola said. “The FBI and our partners worked together to ensure his actions were stopped before there was any risk to public safety.”

BOMB-MAKING MATERIALS FOUND AT NEW ORLEANS AIRBNB POTENTIALLY TIED TO BOURBON STREET TERRORIST: FBI

According to an affidavit filed against Phillips, a Lebanon, Ohio, police officer discovered an IED at a soccer complex at about 12:30 a.m. Sept. 22, 2024.

Just before the discovery, the officer saw two men in their early 20s leaving the parking lot of the complex in a silver SUV, which was originally parked in the lot. The driver was described by police as having long curly hair.

The officer made a traffic stop and told the two men to leave the parking lot since the complex was closed, the affidavit noted.

FBI CONTINUES TO SEARCH FOR JAN. 6 PIPE BOMB SUSPECT 3 YEARS AFTER US CAPITOL RIOT, OFFERS $500K REWARD

Once the two men left, the officer continued to drive in the parking lot and located an IED where the SUV had been parked, court documents allege.

“The IED had wires running from a pile of white powder to a control switch,” the affidavit states. “The control switch had a red light on when the LPD Officer discovered the IED. After encountering the device, the LPD Officer attempted to locate the two males but could not. The officer contacted Butler County Bomb Squad (BCBS) to seize the IED.”

BCBS discovered that the residue on the device contained nickel hydrazine nitrate, while the white powder contained erythritol tetranitrate.

FBI RELEASES VIDEO SHOWING JANUARY 2021 PIPE BOMB SUSPECT PLANTING DEVICE OUTSIDE DNS, RNC OFFICES IN DC

As they tested the IED detonator, it exploded, breaking the handheld chemical identification device.

With the FBI’s help, investigators used cellular data to track Phillips’ phone to the parking lot between 12:15 a.m. and 12:21 a.m. The same phone allegedly sent two texts shortly after the SUV encountered police, one at 12:36 a.m. and the other at 12:40 a.m.

On Dec. 2, 2024, Phillips reportedly got a driver’s license photo, which the affidavit said shows him with the same curly hair the officer saw when he encountered the driver.

Investigators executed a search warrant on the Apple iCloud account associated with the phone, which resulted in a video from April 5, 2024, showing two unidentified men in a parking lot under streetlights, near portable restrooms and a soccer net.

One of the men could be heard counting down to one, before an explosive device detonated. In another video appearing to be from the same incident, an unidentified man says, “James, we gotta go,” and “James, come on.”

FBI FOUND 150 BOMBS AT VIRGINIA HOME IN DECEMBER, PROSECUTORS SAY

The video then shows a hole in the ground, which investigators say was the result of the previous explosion. The two men are then seen picking up the debris and leftover components. GPS data from the metadata of the video shows the video was shot in the parking lot of the same soccer complex in Lebanon, where the police officer encountered the IED months later, the affidavit notes.

Additional photos and videos of explosions were reportedly found on the iCloud account from July 21, 2024, including the destruction of a car.

In one of the videos, investigators wrote, Phillips is seen holding a detonation device as another man counts down from five to one.

“After Phillips presses the detonation device, a large explosion is heard in the distance, and an unidentified male can be heard saying, ‘It blew the car above the tree line,’” the affidavit said. “Additional photos and videos taken on July 21, 2024, show an explosion followed by photos of the destruction of a car that appeared to be destroyed from the explosion.”

The investigation later revealed to detectives that Phillips bought “precursor chemicals and materials for homemade explosives,” which were shipped to his home in Mason and another residence of his in Oxford.

His iCloud account also allegedly had recipes and notes on how to construct explosive devices, the affidavit claims.

Photos also allegedly show Phillips constructing explosive devices in a shed in the woods.

Phillips is expected to appear in court Friday for a bond hearing and will remain in custody until then.