Investigators analyze clues over Tennessee blast

US investigators are analyzing hundreds of tips and leads relating to a large explosion that rocked the city of Nashville, Tennessee on Christmas Day.

Three people were injured in the Friday morning blast, which has been linked to a recreational vehicle.

The vehicle arrived at the location five hours before the incident. A warning of an imminent explosion was heard immediately before the blast.

The FBI has released a photo of the vehicle as it asks the public for information.

Investigators told reporters on Saturday afternoon that they have obtained about 500 pieces of information and objects, including what appear to be human remains found at the scene.

They also said more than 40 buildings nearby were damaged and communications have been disrupted.

The blast occurred in a shopping district with many restaurants and retail shops. Authorities have cordoned off the area until Sunday as the investigation continues.