Police hunting a sex attacker who targeted a teenage girl in broad daylight are still trying to trace a key witness. 

The 16-year-old was attacked from behind in Fairview Close, Walthamstow, and sexually assaulted at the junction with Millfield Avenue at around 4pm on May 5. 

She managed to push the suspect away and run away. 

Detectives have appealed for a woman seen walking her dog in the area at the time may hold vital information.  

Detective Constable Rob Bushell, from Waltham Forest CID, said: "This was a horrible assault that has left a young girl traumatised. 

“We believe that a white lady with short hair was walking her dog on the day of the attack and may have witnessed the incident.  

"We would urge her to come forward." 

The suspect is described as a white man, aged in his late 30s, about 5ft 7ins and of skinny build. 

He was wearing black rimmed glasses and dressed in all black clothing, with brown gloves. 

Anyone with information is asked to call police on 0203 276 0968 or 07785 530 686, quoting reference: 4908870/15. 

Crimestoppers can be contacted anonymously on 0800 555 111.