An explosion that shook downtown Nashville and injured at least three people Friday appears to have been "an intentional act," police said, as officials pointed to a suspicious vehicle that blew up at approximately 6:30 a.m. local time.

The FBI is investigating along with local officials and the Bureau of Alcohol, Tobacco, Firearms and Explosives, and the city of Nashville activated its Emergency Operations Center.

"This appears to have been an intentional act," Metro Nashville Police Department tweeted. "Law enforcement is closing downtown streets as investigation continues."

Officers first responded to the area after receiving a report of shots fired. They called in the bomb squad after seeing the suspicious vehicle, which later exploded.

As of late Friday morning, police did not know if anyone had been inside the vehicle at the time of the explosion, and they were not yet able to confirm that shots were actually fired.

The investigation is now being led by the FBI's Memphis field office, and a spokesperson for the Department of Justice said Acting Attorney General Jeff Rosen "directed that all DOJ resources be made available to assist in the investigation."

"Right now, it’s a public safety concern, to make sure everybody is accounted for and to make sure the spread of the fire doesn’t go any further," Michael Knight, a spokesman for the ATF in Nashville, told The Associated Press.

Law enforcement officials sealed off the downtown area and police dogs searched the area for any secondary devices. Police said they were also searching buildings in the area.

A spokesperson for TriStar Centennial Medical Center said that they have one patient in stable condition, and Nashville General Hospital said that they do not have any patients who came in because of the blast.

Officials earlier said that three people had been transported to local hospitals, but that their injuries were not critical.

The blast caused noticeable tremors in the surrounding area and black smoke to rise.

Buck McCoy, who lives near the area, posted videos on Facebook that show water pouring down the ceiling of his home. Alarms blare in the background and cries of people in great distress ring in the background. A fire is visible in the street outside. McCoy said the windows of his home were entirely blown out.

"All my windows, every single one of them got blown into the next room. If I had been standing there it would have been horrible," he said.

"It felt like a bomb. It was that big," he told The Associated Press.

"There were about four cars on fire. I don’t know if it was so hot they just caught on fire, and the trees were all blown apart," he said.

"The entire @WKRN studio just shook," the outlet's alert desk anchor Josh Breslow tweeted. "Anyone else in Nashville just feel any weird shaking ??"

According to social media posts, the explosion resulted in significant damage to a building that was on fire, with dozens of people evacuated. (Fox News)

•PHOTO: A vehicle burns near the site of an explosion in the area of Second and Commerce in Nashville, Tennessee, U.S. December 25, 2020. Andrew Nelles/Tennessean.com/USA TODAY NETWORK via REUTERS. NO RESALES. NO ARCHIVES - RC2EUK92BW23

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