The death toll from a bus collision in northwest China's Ningxia Hui Autonomous Region on Monday has risen to 12, according to local traffic police.

The latest fatality occurred when one of the injured died in hospital, said the police, adding 31 people, rather than previously reported 25, were injured.

The accident occurred at 12:17 PM on Hui'anpu Section of National Highway 211 in Yanchi County, causing one bus to plunge off a bridge.

Eleven passengers died at the scene, said police.

An investigation into the cause of the accident is under way.

(Xinhua News Agency August 29, 2006)