INDIANAPOLIS (AP) _ Officials say a malfunction in an aluminum heating machine caused an explosion and small fire at an Indianapolis factory.

No injuries were reported from the explosion about 2 a.m. Tuesday at MidAmerica Extrusions on the city's east side.

Fire officials tell Indianapolis television stations the heating machine malfunction sent a fireball through a vent to the factory's roof. Workers were evacuated from the factory and firefighters were soon able to put out the blaze.

Officials say the process will be shut down until state workplace safety inspectors check the equipment involved in the fire.