DETROIT (AP) — Under pressure from U.S. safety regulators, Ford is expanding a recall of small and midsize cars to fix door latches that may not stay closed.

The recall now covers almost 546,000 Ford Fusions and Lincoln MKZs from the 2013 and 2014 model years, and Ford Fiestas from 2011 to 2014.

Ford Motor Co. added about 156,000 Fiestas to a recall announced a week ago. It also determined that some of the Fusions and MKZs under recall were made at a factory near Detroit. Previously the company thought all the cars were made in Mexico.

Ford says a broken spring part can stop the doors from latching properly. The doors also can open while the cars are in motion, increasing the risk of injury.

Earlier this week, the U.S. National Highway Traffic Safety Administration warned owners of the cars to get them repaired as soon as they get a notice from Ford. The company said notices should start arriving the week of May 18. Dealers will replace all four door latches for free.

Ford reported two minor injuries from unlatched doors bouncing into people when they tried to close them. There also was one crash when a door opened and hit another vehicle in a parking lot.

NHTSA said that if owners find it difficult to close doors, their cars should not be driven, even if it appears as if the doors have latched. Instead, the cars should be towed to a dealership, the agency said. Also, NHTSA warned that if a door pops open while the car is in motion, drivers should pull over and have it towed to the nearest dealer.