An early Christmas morning explosion in downtown Nashville is being called "intentional" by officials. Officials said at least three people were minorly injured and dozens of buildings were damaged. 

Nashville Police Chief John Drake said possible human remains were found near the explosion site.

The explosion happened around 6:30 on Friday morning near Second Avenue and Broadway and Commerce Street.

The explosion was from an RV parked at 166 2nd Avenue North at the AT&T building. The damage was causing widespread cell phone outages, including in the Chattanooga area.

Police said they do not know if anyone was in the RV when it exploded. 

Police said there were announcements coming from the RV before it exploded. Police were working to clear the area and a bomb squad was en route to the site when the explosion occurred. One officer was knocked off his feet by the blast. 

"We think lives were saved by officers clearing the streets," said a police representative.  

Police said they are reviewing downtown cameras as part of the investigation. 

Officials said the bomb dogs are going through the downtown area as a precaution to search for other explosives, but none are suspected at this time. 

Several of the buildings on Second Avenue have structural damage, said officials.

The FBI is calling it a "massive crime scene." 

Tennessee Governor Bill Lee tweeted, "Early this morning, an explosion occurred in downtown Nashville around Second Avenue and Commerce Street. Federal, state and local law enforcement partners are on the scene to investigate what we believe was an intentional act.

"We will supply all of the resources needed to determine what happened and who was responsible. Please join @MariaLeeTN and me in praying for those who were injured and we thank all of our first responders who acted so quickly this morning."

"President Trump has been briefed on the explosion in Nashville and will continue to receive regular updates," White House deputy press secretary Judd Deere said. "The President is grateful for the incredible first responders and praying for those who were injured."

Agencies investigating include Metro Nashville Police Department, the FBI, and ATF. 

A $10,000 reward is being offered for anyone that can provide information or leads regarding the event. Visit www.fbi.gov/nashville. "We need your leads, we need your help. We will find out what happened," said an FBI representative.