A tanker truck exploded on an interstate highway in downtown Memphis early Friday, killing at least five people and setting several houses on fire, a fire department spokesman said.

At least five homes in a residential area caught fire on both sides of Interstate 240 when the tanker exploded, apparently after a traffic accident, said Capt. Benny McDow of the Memphis Fire Department.At least five deaths were confirmed, but there probably will be several more, McDow said. Rescue workers predicted "numerous casualties," he said. The identities of the victims were not yet known.

Officials had not determined what the truck was carrying.