A Red Cross truck transporting blood caught fire in Bethesda Sunday evening, according to Mongomery County Fire and Rescue spokesman Assistant Chief Scott Graham.

The incident happened around 7 p.m. near the intersection of River Road and Wilson Lane.

The fire started underneath the vehicle and was extinguished quickly, Graham said. It wasn't clear how it started.

Montgomery County Fire and Rescue stayed on the scene to help Red Cross transport the contents of the truck into another vehicle, Graham said.

A spokesman for the regional Red Cross blood supply couldn't be immediately reached.