Toyota Motor Corp. is halting production at 12 of its domestic plants as Japan struggles to recover from a 6.8-magnitude earthquake that rocked the island nation July 16.

Affected Toyota plants will be stopped for a half day July 19 and all day July 20 after the quake in northwestern Japan damaged factories making piston rings for key supplier Riken Corp., Reuters reports.

But Toyota is not the only Japanese auto maker to suffer effects from the quake, which killed nine people and injured hundreds of others.

Riken also supplies piston rings to Honda Motor Co. Ltd., Suzuki Motor Corp., Mitsubishi Motors Corp., Mazda Motor Corp, Nissan Motor Co. Ltd. and Fuji Heavy Industries Ltd., the maker of Subaru cars.

The supplier, which is said to control about 70% of the Japanese market for seal rings, has two piston ring plants and nine affiliated plants in northwestern Japan.

Honda has yet to determine exactly how its operations would be affected by damage at Riken’s facilities, saying only that some of its car and motorcycle production could be suspended next week. However, an unnamed Honda executive tells Reuters the auto maker may seek the needed parts from an alternative supplier.

During a news conference addressing the situation, Honda Chief Executive Takeo Fukui says the situation still is under investigation. “(We) don’t know how big the impact will be.”

Suzuki, which makes cars and motorcycles, says it will suspend production for three days at five Japan-based plants – including two car assembly sites – beginning July 19. The shutdown will result in a production loss of some 10,000 cars and 5,000 motorcycles, a spokesman says.

Fuji says it will halt production at its mini-vehicle plant from the second shift July 19, until July 21, resulting in a loss of 1,500 units.

Nissan, Mitsubishi and Mazda say they are still accessing the situation.