Police are appealing for help from the public after a female student was attacked as she was walking home in Exeter.
The 22-year-old Chinese woman is a student at the University of Exeter.
She was walking back from work in the city centre in the early hours of Sunday morning when she was grabbed from behind by a man.
She broke free and screamed as three male students approached and the offender ran off.
The attack took place on the junction of Prince of Wales Road with St Germans Road at about 0330 BST.
Police are keen to speak to the men who gave assistance and would also like to hear from anyone else who was in the area at the time.
The attacker was described as being in his 20s and quite tall.