A man attempted to sexually assault a teenager near South Harrow underground station.

The victim, a 17-year-old girl, was walking with friends near the station at around 3am on Saturday, January 16, when a man passed them a few times in a car.

He then got out the vehicle and walked past the group a few more times.

The victim's friends got on a bus and she began to walk home alone down Northolt Road.

She turned into an alley just off Petts Hill and the same man grabbed her and tried to pull her jeans off.

The victim shouted for help and fought against the man before he fled back down the alley towards Petts Hill.

Her attacker is described as Asian, aged between 19 and 28, 5ft 6ins tall, of skinny build with a shaved head around the back and sides and long black hair on the top.

He was wearing a black puffer jacket possibly with red on the arms and jeans.

Detective Constable Chris Dover, from Ealing CID, said: "Although this incident took place in the early hours, Northolt Road is a main thoroughfare which would have had many cars and people using it.

"This man may have been loitering in the area for sometime so I am appealing for anyone who was in the area at the time and noticed someone acting suspiciously to contact me."

Anyone with information is asked to contact Ealing CID via 101. Alternatively, people can contact Crimestoppers anonymously on 0800 555 111 or online at crimestoppers-uk.org.