Police want to trace a man who helped a teenager after she was sexually assaulted in Oxford city centre this morning.

The 18-year-old woman was walking along Magdalen Street East, near to the bus stops by Broad Street, when she was grabbed by an unknown man.

The woman screamed and a member of public intervened and the attacker ran away.

The attacker was is in his 20s, with a pink or light red top and dark hair.

Det Con Iain Spencer said: “The man who came to the woman’s assistance left after he had made sure she was safe, and we are very keen to speak to him.

“He introduced himself as Bruno, spoke with a foreign accent, and was wearing glasses.

“I would also like to hear from anyone who was in the area at the time who may have seen this incident, or anyone who may have seen the man after he fled the scene.”

A 25-year-old man has been arrested in connection with the incident and is being questioned by police.