The government said Sunday it is investigating reports of engine fires in the Chevrolet Cruze small car and Jeep Wrangler SUV.

The fires haven't caused any injuries but have destroyed at least six vehicles. NHTSA is investigating the 2011 model year Cruze and the 2010 model year Wrangler.

The National Highway Traffic Safety Administration has received two reports of fires in the 2011 Cruze. In both cases, owners reported that the fires began while the cars were moving, and in both cases the cars were destroyed.

According to complaints filed on NHTSA's Web site, a driver with a 2011 Cruze Eco was 30 miles into a 43-mile trip last month when smoke started coming out from under the hood. As soon as the driver stopped, flames began shooting out from the car.

"The car was totally engulfed within five minutes of stopping, and it was only after the first sign of fire was visible that the warning light on the dashboard illuminated," the driver told NHTSA. NHTSA doesn't post drivers' identifications on its site.

General Motors Co. spokesman Alan Adler says the company knows of no deaths or injuries related to the issue. GM is cooperating with the investigation. The company sold approximately 177,000 Chevrolet Cruzes from the 2011 model year.

NHTSA also has received eight reports of fires in 2010 model year Wranglers. Most began when the vehicles were moving, and four owners reported that their vehicles were destroyed.

The owner of a 2010 Wrangler told NHTSA that the vehicle was parked and running when it suddenly turned off. The owner was attempting to restart the vehicle when someone outside the vehicle began yelling that it was on fire.

"Once out of the Jeep I looked under it and saw and unknown liquid burning down to the ground from the engine area. I attempted to extinguish the fire with water but I was unsuccessful. Within minutes it was a total loss," the owner said, according to NHTSA's documents.

Chrysler Group spokesman Nick Cappa says the company is aware of the incidents but knows of no accidents or injuries related to the issue. Chrysler is cooperating with the investigation. The company sold 131,000 Wranglers from the 2010 model year.

Cappa said that vehicle fires are complex and can happen for various reasons, including some that have nothing to do with the vehicle itself. Poor maintenance, improper vehicle use or the installation of aftermarket equipment can all cause fires, he said.

"The 2010 Jeep Wrangler meets or exceeds all applicable federal safety standards and has an excellent safety record," Chrysler said in a statement.

NHTSA investigations can lead to vehicle recalls.