HOUSTON -

Two cars inside a northwest Houston car shop caught fire Tuesday, igniting the shop.

Flames broke out around 3:15 a.m. at an automotive shop on Hempstead and Karbach.

Houston firefighters were called to the scene and when they arrived, firefighters said a car was already burning. Investigators said the flames spread to the back of the shop.

The building fire was quickly put out, but officials said the car fire continued to burn and then spread to a second vehicle. Both cars were put out about 15 minutes later.

Authorities said no injuries were reported.

Arson investigators were searching for the cause of the fire.