POLICE have launched an investigation after two women were raped and two others sexually assaulted.

The two sexual assaults happened in Trowbridge on Friday, the same night that a 15-year-old girl was raped in the town and the night after another teenager was raped in War-minster.

DS Nick Shorten, of Chippenham Police, said: "It is extremely unusual to have this number of assaults in one night and we are taking it very seriously."

On Thursday night in Warminster a 16-year-old girl from Melksham was raped outside Oscars nightclub.

DS Shorten said: "CCTV cameras show that when she came back to the front of the nightclub she was very distressed and told her friends immediately what happened to her."

Police are anxious to trace anyone who heard what the girl was saying and a group of youths who confronted a man as he got into a taxi.

Police are not ruling out that the two assaults in Trowbridge may be linked.

In the first attack a 16-year-old girl was treated at the Royal United Hospital in Bath in the early hours of Saturday morning for the suspected affects of drugs.

She claimed that someone had put something into her drink while she was at Terry's Nightspot and that she was then assaulted.

Police are anxious to trace two men called Mark and Sean who were with the victim that night.

At 1.40am the same night, about half an hour after the first incident, police were called after a woman was heard screaming hysterically in the back garden of a house at Alma Street.

The 32-year-old, who had also been at Terry's Nightspot, said she was followed by a stranger who then subjected her to a serious sexual assault.

Earlier on Friday evening a 15-year-old girl from Trowbridge was enticed into the churchyard at Back Street in Trowbridge at 11.15pm.

A 22-year-old Trowbridge man was arrested on Saturday in connection with the incident in the churchyard but has been ruled out of the investigation into any of the other incidents. He has been released on police bail.