Ford has warned rental car companies and other owners of 2021 Ford Expeditions and Lincoln Navigators in the US to park their vehicles outside due to the risk of fire.

The automaker has confirmed 16 fires, mostly in vehicles that were unattended. Fourteen of these fires were in rental cars.

“Until further notice, owners of these affected vehicles should not park them inside – they should only be parked outside and away from homes and other structures. Fires have occurred in vehicles that were parked and turned off,” a statement released through the NHTSA said.

“More than 39,000 vehicles are affected, and at this time there is no known cause or remedy.”

A similar warning was issued some months ago for the Chevrolet Bolt EV following a series of battery pack fires.

Ford said affected vehicles were built between 1 December, 2020 and 30 April, 2021 and “investigations are ongoing”.