DETROIT - Ford has issued three recalls of more than 350,000 vehicles in North America, including nearly 3,000 in Canada and 39,000 in the U.S. due to a risk the engines could catch fire.

Transport Canada said in a recall notice Thursday that some 2021 Ford Expedition and Lincoln Navigators could catch fire in the engine compartment, even while parked with the ignition off.

Ford said in U.S. government documents posted Thursday that it doesn't know what's causing fires in some of the SUVs.

The automaker has reports of 16 U.S. fires under the hood, 14 in rental company vehicles. One person was burned. It's recommending that the SUVs be parked outdoors and away from buildings. So far it hasn't developed a repair for the fires, which appear to start at the back of the engine compartment on the passenger side.

Of the 16 fires, 12 happened while the SUV engines were turned off, Ford said in a prepared statement. The company says it has no reports of fires extending to any buildings.

The number of fire incidents in Canada wasn't immediately available.

Ford said it's not instructing owners to stop driving the SUVs, although those who might not be able to follow the park outdoors instructions should contact their dealer or the company.

Ford said it's treating the recall urgently and will use apps and mail to notify customers as soon as it develops a list of vehicle owners and addresses.

“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.

Ford began investigating fire reports on March 24. It said the fires appear to be limited to SUVs built from Dec. 1, 2020 to April 30, 2021. The company said it has no fire reports from vehicles built before or after those dates.

The automaker also is recalling about 310,000 heavy-duty trucks in the U.S. and nearly 25,000 in Canada because the driver's airbag may not inflate in a crash.

The recall covers certain 2016 F-250, 350, 450 and 550 trucks. Dust can get into the airbag wiring in the steering wheel, disconnecting the electricity. Dealers will replace steering wheel wiring. Owners will be notified by mail starting July 5.

And the company is recalling 464 electric Mustang Mach-E SUVs from 2021. There were no units subject to that recall in Canada. A software problem can cause unintended acceleration, deceleration or a loss of drive power in all-wheel-drive vehicles.

Ford said in documents posted Thursday by the National Highway Traffic Safety Administration that the powertrain control computer may not detect a software error.

The problem will be fixed by dealers or by an online software update. Owners will be notified by letter around May 30.

- With files from The Canadian Press.