The Tour of Qinghai Lake 2016 kicks off in Xining, Qinghai on July 17, 2016. [Photo/Xinhua]

Six professional cyclists were injured as they were sprinting toward the finish line after a bystander trespassed on the course of the Tour of Qinghai Lake 2016 on Sunday.

The incident occurred during the last minutes of stage one of the race, according to Bai Shide, head of security at the tour and deputy director-general of Qinghai province's Department of Public Security.

The cyclists began sprinting as a group during the last lap of the six-lap circuit race in Xining, the capital city of Qinghai, when a bystander threw himself in front of them. In less than a second he was hit by the pack, leading to a pileup of bikes.

Initial investigations showed that the race's security department was to blame. A number of officials and the police officers responsible have been suspended, according to the event's official microblog account.

The injured athletes, along with the 19-year-old suspect surnamed Mi, are receiving treatment. Eyewitnesses suggested that the man might have a mental illness, according to a report by Legal Evening News.

Liang Shuang contributed to this story.