A bus reportedly carrying at least 43 people rolled down a valley after colliding with an SUV Monday in south China's Guangxi Zhuang Autonomous Region. The number of casualties were not known yet, police said.

The crash happened at about 3 p.m. on the Shuinan Highway linking Shuiren in Hechi City and Nanning City, the regional capital, according to Hechi police.

The bus, after going off the road, rolled down a ravine 300 meters deep. The driver of the SUV, the only person in the vehicle, was found seriously injured.

At least 43 people were in the bus, police said, without revealing how many people survived.

Traffic police, as well as fire-fighting and emergency treatment teams were working to rescue the bus victims as of 5 p.m..