Tires that may accidentally have been cut by a narrow assembly line are causing Ford Motor Co. to recall 50,000 brand new Explorers.

It's the second recall of a 3-month-old redesigned model that was scrutinized to prevent such problems after last year's Firestone tire recall.

Included in the recall are 50,000 four-door Explorers built at Ford's plant in Louisville, Ky.

When the sport utility vehicles were loaded too far to the right on the conveyor belt, it left cuts five to nine inches long and half an inch deep in one or both of the right tire treads.

The cuts are cosmetic and do not affect tire performance, according to a Ford official, who commented on condition of anonymity.

The official said the company has no reports of accidents or injuries because of the problem.

The SUV is also made at a St. Louis plant, but it had a different conveyor system that could accommodate the two-inch wider models. Ford has widened its conveyor belt in Louisville by three inches.

The automaker began shipping the SUVs in mid-February and many may still be on dealer lots.

Ford plans to send a letter to all owners by the end of May and will check and replace damage tires for free at its dealerships.

The tires involved are Goodyear and Michelin brands. Ford stopped putting Firestone tires on all its Explorers last year after Bridgestone/Firestone Inc.'s recall of 6.5 million tires.

In April, Ford had its dealers pick up 56,652 new Explorers and Mercury Mountaineers because the rear liftgate windows could break when shut.