A minibus carrying mentally disabled people tumbled off a road and dropped about five meters into a wooded area Monday morning in western Japan, leaving 10 of the 18 people aboard injured, police said.

The accident took place around 10:10 a.m. in Izumisano, Osaka Prefecture, as the bus was heading to a nearby welfare facility. It was travelling on a road without a railing guard.

All of the 18 people on board, aged between their 20s and 60s and including the 67-year-old driver and a member of staff from the facility, were rescued from the bus, which rolled upside down.

The police suspect the driver's negligence as the cause of the crash, after he said he pulled the bus off to the left of the one-lane road when he saw a vehicle coming in the opposite direction.

"This is not a busy road," a woman living nearby said. "So many cars run at a high speed. We've had collision accidents before. But I never thought that such an accident would take place."