A 33-year-old woman was lucky to escape serious injury when she fell in front of a bus after colliding with a jogger, police have said.
Dramatic CCTV of the incident shows a man running along Putney Bridge, west London, and appearing to push the woman into the road.
The oncoming bus is forced to swerve into the adjacent lane to avoid hitting her.
Investigating officer Sergeant Mat Knowles said: "The victim was put in extreme danger when she was knocked into the road.
"It was only due to the superb quick reactions of the bus driver that she was not hit by the vehicle."
The Metropolitan Police said the bus stopped and passengers tended to the woman - who received minor injuries - following the incident on Friday, May 5 at about 7.40am.
Officers said the jogger ran the other way across the bridge around 15 minutes later and the victim attempted to speak to him, but "he did not acknowledge her".
An appeal has been launched for witnesses or anyone who recognises the jogger in the CCTV.
The jogger is described as white in his early to mid-30s, with brown eyes and short brown hair.
He was wearing a light grey T-shirt and dark blue shorts.
Anyone with information is asked to call police on 101 or Crimestoppers anonymously on 0800 555111.