Six people were killed and a dozen injured Thursday when two buses collided in Hangzhou city, East China's Zhejiang Province.

Rescuers prepare to remove a bus out of the expressway after a crash which killed six people near the Hangzhou International Airport in Hangzhou, Zhejiang province, Dec 16, 2010. [Photo/Xinhua]

The two buses crashed near the toll gate on the expressway near the Hangzhou International Airport in Xiaoshan District at 6:15 pm, said district police.

Officials said the accident occurred when a bus with no passengers skidded out of control and crashed into a bus filled with passengers, as one bus landed on top of the other.

More than 10 injured passengers were lifted out of the bus. Some of them were seriously hurt, according to rescue workers.

Rescue work is still underway. The exact number of casualties remains unknown.

Heavy snow hit Zhejiang povince Wednesday and Thursday as roads remain very slippery.