Under pressure from U.S. safety regulators, Ford is recalling about 2 million F-150 pickups in North America because the seat belts can cause fires.

The recall covers certain F-150 trucks, the best-selling auto in the United States, from the 2015 through 2018 model years, the company announced Thursday.

The company reported 17 cases of smoke or fire in the United States and six in Canada, but said it's not aware of any injuries or related accidents.

The U.S. National Highway Traffic Safety Administration began investigating the fires last month after getting five reports. Fires destroyed three trucks.

Ford says some seat belt pretensioners can generate excessive sparks when they tighten the belts before a crash. That can ignite gases inside a support beam and cause insulation and carpet to catch fire.

Affected vehicles were built between 2014 and 2018 at Ford plants in Michigan and Missouri.

Dealers will remove insulation and install heat-resistant tape. Owners will be notified starting Sept. 24.