A vegetation fire in rural Redwood Valley Tuesday night launched firefighters and a Mendocino County criminal investigation into possible drug involvement, according to emergency officials.

The fire was on Appaloosa Way, in the valley northwest of Ukiah.

Firefighters were called at 6:49 p.m. to a vegetation fire at a remote location out on Appaloosa, near Tomki Road, according to a Cal Fire spokesman.

The fire was small but initial reports indicated a drug lab may have been involved and a hazardous materials crew also was called to respond.

That led to involvement by the Mendocino County Major Crimes Task Force, which is now investigating.