A 17-year-old girl has been sexually assaulted by a man as she walked across a park in Cambridge.
The girl was walking in an area of the city's Sackville Close early on Saturday morning when she was grabbed from behind.
She struggled to escape but the attacker pushed her to the ground and sexually assaulted her before running off when the girl started screaming.
The attacker was white, of medium build and aged in his late 20s to early 30s.
He was wearing a grey hooded top.
Police appealed for anyone with information to contact officers.