Washington, Dec 28 (IANS): A 63-year-old man identified as the "bomber" who detonated a recreational vehicle (RV) packed with explosives on Christmas morning in the US city of Nashville, was killed in the blast, authorities said.

"Anthony Warner is the bomber. He was present when the bomb went off, and he perished in the bombing," Xinhua news agency quoted US Attorney Don Cochran as saying at a news conference on Sunday.

DNA found on human remains in the wreckage matched Warner, Tennessee Bureau of Investigation (TBI) Director David Rausch said Sunday.

The TBI was involved in testing the evidence.

The motive behind the bombing has not been released, as the investigation is still ongoing into the blast which took place in the morning of December 25 on 2nd Avenue North in downtown Nashville, according to Federal Bureau of Investigation (FBI) Special Agent for Public Affairs Doug Korneski.

A recorded message that indicated a bomb would explode in 15 minutes was heard coming from the RV before it exploded.

The message had a voice that sounded like that of a woman and repeated with an undistinguished American accent in a monotone characteristic of public announcements like, "this area must be evacuated now" and "if you can hear this message evacuate now" interspersed with a countdown.

The following day, federal agents searched what was confirmed to be Warner's home in Antioch, Tennessee, about 11 miles from the site of the blast.

Officials believed there was no indication that anyone else was involved in the explosion.

The explosion caused structural damage to several buildings, fires and power outages in the region.

Three people were injured but not in critical condition.