HOUSTON - A cargo train derailed in the US city of Houston Saturday, forcing evacuations without injuring anyone, local media reported.

The derailment occurred before 8:00 pm (0100 GMT Sunday) in east Houston. The fire department evacuated five blocks around the accident afterwards, local TV KTRK reported.

KTRK, citing authorities, said the derailment involves three cars, with one of them leaking an unknown substance. Residents were allowed to return home hours after evacuation, the station said.

No injuries have been reported in the accident. It remains unclear what had caused the derailment.