A woman suffered a serious sexual assault at knife point as she walked along a footpath in Peterborough.
The victim, in her 20s, was walking towards Ivatt Way from Lincoln Road, near to Rhubarb Bridge, when she was approached by a young man.
He threatened her with a knife before sexually assaulting her. The victim managed to escape uninjured and alerted police.
The attack happened between 11am and 11.30am on Saturday 30 September. A team of detectives is investigating the attack and there will now be extra patrols in the area.
Police say the attacker is described as being of Asian appearance, in his late teenage years, about 5'8", slim, short black hair and a small moustache. He was wearing black jeans and a black jacket.
Detective Sergeant Gordon Blair said: "This was a terrifying experience for the victim who was not injured but extremely upset and shaken.
"I hope someone may have seen a youth matching this description at the time. I would urge anyone with information, no matter how insignificant it may seem, to contact police without hesitation."