A 53-year-old woman was sexually assaulted as she walked home in Bounds Green last week.
The victim was attacked as she walked down an alleyway through Sussex Works to get on to Cline Road at approximately 6.20pm on Thursday, February 6.
She was grabbed from behind and rugby-tackled to the ground by her assailant, who lay on top of her.
The man ran off after 53-year-old began to scream.
The woman described her attacker as a chubby, light-skinned black man, aged approximately 18 to 25, with a broad nose.
He had messy, long, thick curly black hair and was wearing grey tracksuit bottoms and a matt, dark-coloured jacket.
Detectives are appealing for anyone with information to call them on 020 3276 3071 or, if you wish to remain anonymous, Crimestoppers on 0800 555 111.