A police chief yesterday warned women to stay away from Ipswich's red light district as fears rose that a serial killer was targeting prostitutes.

Detectives in Suffolk said two prostitutes had been murdered, another found dead and two were missing.

Jacqui Cheer, Assistant Chief Constable of Suffolk, said prostitutes alone on the streets of Ipswich were "in danger".

"My message to you is simple - stay off the streets," she said in a message to prostitutes. "If you are out alone at night, you are putting yourself in danger."

Gemma Adams, 25, of Ipswich, vanished in the early hours of November 15. Her naked body was found in a stream at nearby Hintlesham on December 2.

Tania Nicol, 19, also of Ipswich, disappeared on October 30. Her naked body was found in a pond at nearby Copdock on December 8. A third prostitute - a woman in her 20s, not yet named by police - was found dead in a wood at nearby Nacton yesterday. She was also naked.

But police were not linking the death of a woman found in a river near Crowland, Lincolnshire, at the weekend to their inquiry.

Detective Chief Superintendent Stewart Gull, who is heading the inquiry, said police might be looking for a serial killer.

"It is possible," he said. "We are keeping an open mind."

Police said they were also worried about Paula Clennell, 24 - not seen since late on Saturday - and Annette Nicholls, 29 - who has not been seen since December 4.

Mr Gull said Miss Clennell had spoken to a friend late on Sunday but had not been seen since or made contact with police.

"Both of these girls were reported missing as a result of the inquiry - there could be an innocent explanation," he added.

"However in the current climate we are concerned for their welfare and are making urgent inquiries to contact them."

Police yesterday moved the body found at Nacton from woodland where it was spotted by a motorist. Mr Gull said the discovery of the third body was a "deeply disturbing development".

"While we can't formally link the discovery of the body at Nacton with the two murders, the facts speak for themselves," he said.

"At this stage we don't know how long the body may have been at that location."

He added: "Clearly there are some distinct similarities. We have already linked the death of Tania and Gemma - clearly there are significant similarities in the finding of this latest woman."

Police have not yet named the third dead woman, but Mr Gull said she had worked as a prostitute in Ipswich and was thought to be 24.

Mr Gull said more than 100 officers were involved in probably the biggest murder investigation seen in Suffolk.

He said detectives were following a large number of leads, adding: "We have a number of interesting lines of inquiry that we are pursuing."

No one has been arrested, he said.