Toyota Motor Corp. has suspended operations at 12 of 14 plants in Japan due to a systems glitch.

Some 25 assembly lines across a dozen plants have been halted, a spokesperson said Tuesday. Orders for parts can’t be placed due to a malfunction in the production command system, they said.

“At this point we do not believe a cyberattack is responsible,” the spokesperson said, adding that currently the system glitch appears limited to domestic plants.

Toyota’s Miyata plant in Fukuoka prefecture and that of its subsidiary, Daihatsu Motor Co., in Kyoto are unaffected.

Toyota shares fell as much as 0.7% in early Tokyo trading.