(AFP) - An official suffered a serious head injury when caught up in a high-speed collision at cycling's world track championships on Friday, AFP reporters at the scene witnessed.

The International Cycling Union (UCI) official ran onto the oval track to pick up an object a competitor had lost from her bike in a crash when Hong Kong rider Diao Xiaojuan hit him at full speed.

After being treated on the track for 15 minutes, the official was taken away on a stretcher unconscious and bleeding from the head.

The cyclist, who was taking part in the Scratch leg of the four-part Omnium, was herself also taken away in a wheelchair.

The race was restarted 45 minutes later.