Toyota, Honda and Mazda resumed production Tuesday at their domestic factories after key parts supplier Riken, damaged by last week's quake, resumed operations.
Factories of Toyota Motor Corp. and other major automakers had been shut because of a lack of parts following the damage to piston-ring maker Riken Corp.'s plant in Kashiwazaki, Niigata Prefecture, near the epicenter of the magnitude-6.8 quake.
Riken restarted production of some auto parts Monday after workers replaced damaged equipment and restored the factory's gas and water supplies.