An explosion shook the largely deserted streets of central Nashville in the US early Christmas morning, shattering windows, damaging buildings and wounding three people.

Authorities said they believed the blast was intentional, but they do not yet know a motive or target.

Metro Nashville police chief John Drake said police were responding to a report of shots fired when they encountered a vehicle blaring a recording that said a potential bomb was to detonate in 15 minutes.

Police evacuated nearby buildings and called in the bomb squad.

“Shortly after that, the vehicle exploded,” Mr Drake said at a midday news conference.

Surveillance video published on a Twitter account Friday that appeared to be recorded from across the street captured an audio recording that included the warning: “If you can hear this message, evacuate now.”

The blast was captured on the surveillance video seconds later.

Metro Nashville Police Department spokesman Don Aaron said three people were taken to hospital for treatment, although none were in a critical condition.

The Federal Aviation Administration later temporarily halted flights out of Nashville International Airport due to telecommunications issues associated with the explosion.

Authorities do not know whether anyone was in the vehicle when it exploded.

Mr Aaron said earlier that some people were taken to the department’s central precinct for questioning but declined to give more details.

Mayor John Cooper said at a news conference: “This morning’s attack on our community was intended to create chaos and fear in this season of peace and hope.

“But Nashvillians have proven time and time again that the spirit of our city cannot be broken.”

The FBI will be taking the lead in the investigation, said spokesman Joel Siskovic.

Federal investigators from the Bureau of Alcohol, Tobacco, Firearms and Explosives were also on the scene.

The FBI is the primary law enforcement agency responsible for investigating federal crimes, such as explosives violations and acts of terrorism.

At noon, police dogs continued to search cars and buildings in the nearby area.

A man staying in a nearby hotel said that when he heard the blast, he knew it was not a harmless noise.

“It was a very loud explosion,” said Joseph Fafara. “We tried to rationalise it that it was an earthquake or something. But it was obvious it wasn’t an earthquake.”

Black smoke and flames were seen early Friday billowing from the area, which is packed with bars, restaurants and other retail establishments and is known as the heart of central Nashville’s tourist scene.

Buildings shook in the immediate area and beyond after a loud boom was heard.

Buck McCoy, who lives near the area, posted videos on Facebook that show water pouring down the ceiling of his home. Alarms can be heard in the background as well as cries of people in distress.

A fire was visible in the street outside.

Mr McCoy says he heard gunfire 15 minutes before the explosion rocked his building.

He 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.

Two law enforcement officials later said authorities had found human remains in the vicinity of the explosion, it was reported.

It was unclear how the remains are related to the explosion or whether they might belong to the person believed to be responsible or a victim.