Chinese police have kicked off a three-month campaign against road safety hazards involving large passenger vehicles following a spate of deadly accidents in March.

During the campaign, which started Friday, all firms operating long-distance coaches, city buses and tourist vehicles have to undergo strict safety checks, said a statement issued Saturday by the Ministry of Public Security.

Those companies found to have safety risks will have to suspend business until safety hazards are eliminated or their licenses will be withdrawn, said the statement.

The companies should also effectively raise safety awareness among drivers and managers, and ensure all vehicles to work in good conditions, it said.

Four fatal road accidents occurred from March 11 to 16, killing 66 people and injuring 87 others respectively in Xinjiang Uygur Autonomous Region, Tibet Autonomous Region, and Shanxi and Jilin provinces.

Police authorities across China will set up temporary checkpoints along highways and expressways to monitor hazardous moves such as overloading, said the statement.

The campaign was jointly initiated by ministries of public security and transport, and the State Administration of Work Safety.