Ford is recalling more than 39,000 SUVs after 16 under-the-hood fires, the company said.

The recall covers certain 2021 Ford Expedition and Lincoln Navigator vehicles in the United States that were built between December 2020 and April 2021. The company is urging customers to park their cars "outside and away from structures."

Of the 16 reported incidents, 12 cars were off and parked when the fires started. The company said this week 14 of the incidents were in cars owned by rental companies.

Ford said it started investigating the fires in March but has not yet identified a cause. The company said incidents are believed to begin in the back of the engine compartment, near the vehicle's passenger side.

The company has identified one injury related to the recall, but no crashes.

"We are working around-the-clock to determine the root cause of this issue and subsequent remedy so that customers can continue to enjoy using their vehicles," Jeffrey Marentic, general manager of Ford Passenger Vehicles, said in a statement.