A cyclist suffered life threatening injuries after being hit by a patrol car in North Austin Thursday night.

Austin police said one of its officers struck a man in his 20s near North Lamar Boulevard and Rundberg Lane.

They said the cyclist was traveling west on Rundberg when he ran a red light.

Austin Police Department's Joe Munoz said the cyclist did not have bike lights.

"It was dark, and the bicycle didn't have lights on the front and the rear and the bicyclist was wearing dark clothing," he said.

Authorities said the man suffered a substantial head injury.

The man is in serious but stable condition.

The incident is under investigation.