A massive Christmas morning explosion in Nashville is being investigated as "intentional"

A massive explosion that tore through downtown Nashville, TN, on Christmas morning is being investigated as an "intentional" act, according to Metro Nashville Police Department spokesperson Don Aaron.

At least three people have been hospitalized from the blast, Nashville Fire spokesman Joseph Pleasant announced, although none of the victims are believed to be in critical condition. According to the Nashville Fire Department, the explosion was powerful enough to shatter storefront windows several blocks away from the detonation site.

Pictures shared from the scene show black smoke rising from the street, with glass and blackened tree branches scattered across the area.

By midmorning, local and federal law enforcement agencies including FBI and ATF were already at the scene to investigate and assess the damage, Tennessee Gov. Bill Lee announced. The FBI will reportedly lead the massive investigation effort.

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

The blast occurred shortly after 6:00 a.m., while local police were investigating reports of a suspicious vehicle parked in the area. During a short press briefing on Friday morning, Nashville authorities explained that upon arriving to assess the vehicle, police "had reason to call [the] Hazardous Devices unit."

"The Hazardous Devices unit was en route to the downtown area when an explosion linked to that vehicle took place."

Surveying the scene, Nashville Mayor John Cooper estimated that nearly two dozen area businesses had been damaged in the explosion, according to the Tennessean.

"One more event in Nashville's 2020," Cooper added.

Nashville resident Buck McCoy, who lives near the blast site, described the scene to the AP.

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

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

Update, 1:51 p.m. ET: During an afternoon press conference, Nashville police stated that they had initially been called to the scene of the eventual explosion in response to reports of gunfire in the area. Upon arriving, they found the vehicle in question — an RV — broadcasting a message that it would detonate within 15 minutes. Police then set out to evacuate nearby buildings, and were in the process of doing so when the vehicle exploded.

This is a developing story and will be updated as new information is made available.