Police are appealing for help after a woman was grabbed from behind and sexually assaulted.
The attack happened on Ecclesbourne Road at the junction with Bensham Manor Road as the victim, a woman in her 20s, was walking from Thornton Heath station.
As she turned into Ecclesbourne Road, she was grabbed from behind by a man who forced her to the floor and seriously sexually assaulted her.
He fled the scene with another man who was acting as a lookout during the attack, which happened at about 9.40pm on July 18.
The suspect who carried out the attack was black, aged approximately 16, of slim build and around 5ft 4inches.
He was wearing a red cap, red hooded top and blue jeans.
The second suspect is also black, aged approximately 15, of slim build and around 5ft 4inches. He was wearing a black shirt and a woolly hat.
Acting Detective Sergeant Darren Greening from Sapphire, said:"This attack happened at a time when there would have been a number of people walking back from the local railway station.
"Although the whole incident lasted around 20 seconds it would have been very noticeable. If you saw anything of the incident, or two black males running away from the scene, please contact police."
Anyone with information is asked to contact police on 020 8721 4122; alternatively contact Crimestoppers anonymously on 0800 555 111.