An Afghan drove a stolen car onto the ramp area of a British airfield in southern Afghanistan, and caught fire, when U.S. Defense Secretary Leon Panetta's airplane landed there Wednesday, the Pentagon said.

Pentagon spokesman John Kirby said no one in Panetta's party was injured, but the driver in the stolen vehicle suffered burns and was being treated.

Panetta proceeded with his schedule of the day after the incident, which took place in the morning.

Kirby said the driver drove the vehicle, a pickup truck, onto the ramp area of the airfield and into a ditch, where it caught fire. How it caught fire was unclear at the moment.

There's no word on the motives of the incident, and no explosives were found in the vehicle or on the driver.

The authorities are still investigating, and Kirby said there was no immediate indication that the Afghan was attempting an attack on Panetta's party.

Panetta paid an unannounced visit to Afghanistan on Wednesday and visited southern Helmand Province. The visit took place three days after a U.S. soldier entered civilian homes in Panjwai district of Kandahar Province, killing 16.

As part of his schedule, Panetta traveled to Camp Leatherneck, a military base in the desert of Helmand Province, where he addressed some 200 Marines, Afghan security officers and troops from other coalition countries.

According to U.S. media reports, Panetta told the service members: "we will be challenged by our enemies, we will be challenged by ourselves, we will be challenged by the hell of war itself."