A bus carrying Olympic athletes collided with their van in suburban Beijing on Wednesday resulting in three Chinese people being seriously injured.

The 1.40 pm Olympic shuttle bus from the athletes' village to the outlying Shunyi Rowing and Canoeing Park collided with the van about 1 kilometre from the venue, said Gregg Lovell, the Australian rowing team doctor.

"It was a major collision," Lovell said.

"I was half asleep listening to my Walkman at the front of the bus when all of a sudden the van pulled in front of the bus and there was a major collision," he said.

"The bus collided with the van and in turn moved off the road and hit a guard rail," Lovell said.

Three of the four people travelling in the van were critically injured, he said.

The bus was carrying six people, including another Australian who "acted very quickly" to try to help the injured people after the crash.

The two Australians lifted one passenger from the van onto the road but the others were "certainly very seriously injured," Lovell said.