BEIJING, May 1 (Xinhua) -- The Ministry of Public Security (MPS) on Sunday asked the public to heed traffic safety, as Monday marks the end of the International Labor Day holiday.

A total of 12 people were killed and another 10 were injured in a car-bus collision in north China's Inner Mongolia Autonomous Region on Saturday, the first day of the holiday.

The accident happened at about 5:20 p.m. when an unregistered car violated traffic regulations and crashed with a bus on a section of a national road in Arun Banner, Hulun Buir City. All the deaths and injured were from the bus.

According to preliminary investigation, the bus, which was supposed to get vehicle maintenance on Saturday, is suspected of illegal operation. It was used for tourists transportation as a private vehicle, and the driver failed to warn passengers to tie the seat belts.

Traffic management bureau of the MPS warned that drivers should abide by traffic laws and regulations, and plan their routes and return time in advance so as to avoid fatigue driving.

In the meantime, travel agencies should rent qualified passenger vehicles and are responsible for passengers' safety, according to the traffic management bureau.