A Chattanooga shooting may be linked to ISIS, as a Twitter account connected to the Islamic terror group appears to have taken credit for the of bloodshed of Thursday’s deadly shooting.

On Thursday morning around 10:45 a.m., a suspect identified as Muhammad Youssef Abdulazeez opened fire, killing four individuals and injuring three others, ABC News reported. The gunman was also killed, the city’s mayor said.

The shooting took place across two locations, including a Naval Operation Support Center and an Armed Forces Recruiting Center includes recruiting offices for the Army and Marine recruiting office. The locations are about 5 minutes apart, which the FBI said takes about 15 miles to travel by car.

Though authorities initially said there was no indication of terrorism, that changed once more details came to light.

It appears that a Twitter account linked to ISIS may appears to have taken credit for the Chattanooga shooting. It is not immediately clear if the threat is legitimate or simply trying to steal credit for the deadly attack.

The Twitter account also appeared to make threats against other locations, including Berlin.

“A Message SOON SOON SOON #Berlin #merkelstreichelt #ISIS #Hennigsdorf #Bachelorette #newsrw“

The suspect, who was reportedly killed, has been identified as Muhammad Youssef Abdulazeez. Witnesses say the shooter was a white male driving a silver Ford Mustang convertible.

“He had a big, big high-powered rifle. He was opening fire, the Air Force, Marines and Navy offices,” witness Gina Mule told CNN.

The Guardian had other details of the Chattanooga shootings:

“Law enforcement officials told recruiters that they were attacked by a shooter in a car. The shooter stopped in front of the recruiting facility, shot at the building and drove off, said Brian Lepley, a spokesman with the US army recruiting command in Fort Knox, Kentucky. “Television images of a door to the center in a strip mall showed more than a dozen bullet holes in the glass.”

It is still unclear just how long the shooting may have lasted, but one recruiter told the Guardian that he heard 20 or 30 shots.

“We heard one single shot, which kind of sparked our attention. Shortly after that, just a few seconds, the shooter began shooting more rounds,” he said. “We realized it was an actual shooting, so we then initiated our active shooter drill: getting down low to the ground, moving to a safe location. And we waited until everything seemed to be clear.”

FBI special agent Ed Reinhold said the Chattanooga shootings were being treated as an act of domestic terrorism, but the FBI has reportedly not ruled out an international attack. It is unclear the background for shooting suspect Muhammad Youssef Abdulazeez.

[Image via Twitter]