The government, meanwhile, said it was investigating reports that the large sun roof on the Cadillac SRX has shattered while driving at highway speeds, showering passengers with glass.

Mazda said it recalled about 2,000 of the Mazda5s that had already been sold and told dealers not to sell another 700 still on dealership lots. The Mazda5, which seats six but is smaller than a typical minivan, first became available in the United States during the summer.

Production of the vehicle, expected at 10,000 to 15,000 in North America, has been suspended while the company investigates the incidents, the automaker said.

"Safety is our No. 1 priority so we've gotten all the customers into loaner vehicles so they're not without a car for the duration," said Mazda spokeswoman Tamara Mlynarczyk.

The recall is based on three reports of fires, which the automaker said appeared to start around the left rear bumper. Mlynarczyk said the automaker is trying to quickly understand the cause of the problem.

Mazda said owners were told it may take about a month to fix the problem. The potential defect is not believed to affect vehicles in Japan and Europe, Mlynarczyk said.

The National Highway Traffic Safety Administration, meanwhile, said in a posting on its Web site that it had opened a probe into the 2004-2005 models of the Cadillac crossover. It identified 10 reported injuries consisting of minor cuts and scrapes linked to four consumer complaints.

General Motors Corp. spokesman Alan Adler said about 30,000 vehicles had the broad sun roof, which became a standard feature on models with V8 engines in 2005. The sun roof exposes the second row of seats when opened and is about 6 square feet in size.

One owner, who was not identified, told the government that the sun roof collapsed in mid-August, injuring six people while the 2005 model was traveling at 60 mph to 65 mph. The people were treated at a local hospital for cuts.

Adler said the automaker was unaware of the concerns before the government's decision to investigate and was cooperating with the inquiry.

The government also said it was investigating the 1998-2000 models of the Mercedes-Benz SLK230 convertible because of complaints over failing brake lamps. The inquiry involves about 33,000 convertibles.

NHTSA said it appeared that the brake lamp socket can melt and the lamp can burn out.