WASHINGTON – Mazda Motor Corp. said Monday it had halted the sale and production of the 2006 Mazda5 crossover because a potential heat buildup in the exhaust system could lead to a fire.

The government, meanwhile, said it was investigating reports that the large sunroof 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.

The recall is based on three reports of fires, which the automaker said appeared to start around the left rear bumper.

Mazda said owners were told it may take about a month to fix the problem.

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 sunroof, which became a standard feature on models with V8 engines in 2005.

The sunroof exposes the second row of seats when opened and is about 6 square feet in size.