A woman was assaulted after a man performed a sexual act on a bus while staring at her.

On May 27 at around 2.50pm, a woman saw a man emerge from the bushes near a bus stop outside Barnet General Hospital, and both boarded the 307 bus towards Brimsdown.

The victim sat on the lower deck, near the back, and noticed the man sitting adjacent to her and was performing a sexual act on himself while staring directly at her.

The woman immediately stood up, feeling distressed, and got off the bus outside St John the Baptist Church.

Metropolitan Police's roads and transport policing command are investigating, and the suspect is described as a black man, between 30 and 40 years old, with short black hair and a beard.

At the time of the incident he was wearing a grey tracksuit top, black tracksuit trousers and light coloured boat shoes.

The police have released an image of a man they want to speak to.

There have been no arrests.

Any witnesses or anyone with information is asked to contact PC Jay Thorn on 020 7327 4444, via 101 or Crimestoppers anonymously on 0800 555 111 or visit www.crimestoppers-uk.org