The Toyota suspended work at all assembly plants in Japan due to a fault in its production system.

A Toyota spokesperson told the BBC that the company is trying to find the cause of the problem, but does not currently believe it is due to a cyber attack.

On Tuesday morning, Toyota suspended operations at 12 of its 14 assembly plants in Japan.

Later in the day, a spokesman said production at all 14 facilities would be suspended.

The company has not yet said when it plans to restart operations or how much production is expected to be lost due to the outage.

In total, the 14 plants are estimated to account for about a third of Toyota’s global production.

The suspension comes as Toyota’s production in Japan recovers after a series of problems. Its operations were hit last year after one of its suppliers was cyber-attacked. The one-day outage caused a production loss of about 13,000 cars.

Toyota pioneered the so-called just-in-time production system, which keeps costs low but can be vulnerable to problems if parts deliveries are disrupted.