A local train derailed Sunday in western Japan, injuring all 25 passengers and the driver, police said.

The two-car train operated by West Japan Railway Co. fell on its side while traveling early Sunday in mountainous areas between Makiyama and Tamagashi stations in Okayama prefecture, about 340 miles west of Tokyo, prefectural (state) police official Hirofumi Yamazaki said.

Those who were injured had been taken to nearby hospitals for treatment, Yamazaki said.

Kyodo News agency said none of their injuries were life threatening, though two people were seriously hurt.

Investigators found a large rock near the rail tracks which cut through the mountainside, Yamazaki said.

The cause of the accident was still under investigation, but the rock, which apparently had rolled down from the mountain, might have hit the rail tracks and damaged them, he said.