Mazda is to recall 1.2m vehicles in the US for defective ignition switches.

In these vehicles, which date back to the 1990s, grease could accumulate inside the switch, causing overheating and possibly a fire. However, the problem does not occur when the vehicle is in motion.

The recall covers 1992-93 MX-3, 1993-97 MX-6, 1993-95 929, 1993-98 626, 1989-1998 MPV and 1990-96 323/Protégé, USA Today reported.

There have not been any reports of accidents or injuries due to the fault. The company will offer free repairs starting in December.

Globally, 4.9m vehicles have been affected by the problem.