Toyota Motor will gradually resume operations at 12 of its factories in Japan, starting Wednesday morning.

The automaker halted operations at all 14 of its group's domestic plants on Tuesday due to a system failure that made it impossible to order parts.

The company has since been conducting temporary restoration work while investigating the cause of the malfunction.

It plans to resume production at the remaining two plants in Fukuoka and Kyoto prefectures from Wednesday evening.

Meanwhile, Hino Motors has announced that it will halt operations at its Koga factory in Ibaraki Prefecture on Wednesday.

The truck maker says it uses Toyota's system that malfunctioned, and has run out of components.

In March last year, Toyota was forced to stop operations at all of its domestic plants after one of its suppliers was targeted by a cyberattack.

But company officials said that as of now, they do not believe the current issue was caused by a similar attack.

They said they apologize for causing inconvenience to customers, suppliers and others involved.