British detectives hunting a serial killer who preys on prostitutes discovered two more bodies Tuesday, police said, bringing to five the number of young women who have been discovered dead in the last 10 days.

"We can only fear the worst," Detective Chief Superintendent Stewart Gull of Suffolk police said. "The natural assumption is that these are the two missing women."

As part of the investigation into the deaths of three prostitutes in the Ipswich area, detectives were also searching for two other missing women who also worked as prostitutes in Ipswich.

The naked bodies of Gemma Adams, 25, Tania Nicol, 19, and 24-year-old Anneli Alderton were found a few miles apart in rural eastern England.

Police said Alderton — who was last seen on a train — was asphyxiated. It appeared she had been strangled but was not sexually assaulted, police said Tuesday.

The bodies of Adams and Nicol were found in water, which has prevented investigators from determining a cause of death, or whether they were sexually assaulted. It did not appear, however, they suffered a significant trauma or had been asphyxiated, Gull said.

Police had announced a search for Annette Nicholls, 29, and Paula Clennell, 24, who had been missing for about a week.

The first body discovered Tuesday was found by pedestrians at 3:05 p.m. local time on a rural road. That led to a search by police and a police officer on board a helicopter spotted a second body a few hundred yards away in an area described as heavily wooded, rural and secluded.

Police confirmed the first body was naked. There was no word on whether the second body had clothing when it was found.

The killing has stirred memories of the so-called Yorkshire Ripper, one of Britain's worst serial killers. Peter Sutcliffe admitted to killing 13 women, mostly prostitutes, during the 1970s. He was sentenced to serve a minimum of 30 years in prison.

Police suspected a serial killer in the recent cases but weren't ruling out multiple suspects.

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Police were reviewing closed-circuit television footage of the red light district and other areas of Ipswich, which is about 70 miles northeast of London.

Police said there was also no indication that the potential killer or killers were targeting women other than prostitutes.

"We may be looking for one perpetrator. There may be more," Gull said.

Assistant Chief Constable Jacqui Cheer urged prostitutes to stay off the street, and to help police with any information they have.

"If you are out alone at night, you are putting yourself in danger at this time," she said.

The Associated Press contributed to this report.