Police have warned young women to be vigilant at a west Wales resort - a favourite for stag and hen weekends - after a spate of serious sexual assaults.

Dyfed-Powys Police chief inspector Roger Hughes said officers had questioned 11 south Wales men last week in an ongoing investigation into attacks in Tenby.

People need to be responsible when coming to the town and women need to be vigilant

Chief inspector Roger Hughes

"Most people regard Tenby as a very tranquil town, but people are coming to take advantage of the nightclubs and we are having many sexual offences reported to us," he said

Men's magazine Maxim named the Pembrokeshire resort the world's second-best location for stag weekends in 1999.

Detectives are now concerned about the changing face of the traditional family tourist spot - rapidly becoming a favourite with 20-somethings from around the UK.

Over the last few years, Tenby has seen a flood of revellers arriving at its historic shores and is seen as a domestic alternative to Ibiza or Ayia Napa.

Weekends of fun and drink lure stag and hen revellers

This has meant a six-fold population increase at weekends.

But many residents have become upset at the younger generation's "holiday behaviour".

Among the latest incidents, a 17-year-old woman claimed to have been the victim of a sexual assault.

Police said all men arrested had been released pending further inquiries.

"There has been a marked increase in alcohol-linked assaults and it causes a great deal of anxiety," Mr Hughes told BBC Wales.

"People need to be responsible when coming to the town and women need to be vigilant."

An earlier police statement read: "It is known that groups are travelling considerable distances for these events."

There is a lot of unsavouriness on weekends, but afterwards the resort tries to return to normality and families can walk the streets

Tenby Councillor Michael Folland

The town - surrounded by an imposing 13th Century stone wall - is steeped in ancient history and first became popular as a tourist haven in the Victorian period.

But while the influx of young people on stag and hen weekends is good news for many businesses, some in the town are not so welcoming.

Tenby South Councillor Michael Folland told BBC News Online: "It is very disappointing we weren't able to stop these people coming.

'Simulated sex'

"They are not doing us any favours, showing threatening behaviour as they go from pub to pub with their peculiar antics.

"One recently simulated sex with a blow-up doll on a public highway.

"We want a happy summer resort, without those degrading acts.

"There is a lot of unsavouriness on weekends, but afterwards the resort tries to return to normality and families can walk the streets."

Weekends of fun and drink lure stag and hen revellers

Councillor Folland said Tenby Town Council called on hoteliers and bar owners to ban unwanted visitors from their establishments.

But, at a public meeting, several business people blocked that move in favour of an increased weekend police presence, he said.

"A few hotels are benefiting and some hoteliers are enjoying the sound of tills ringing, but it could destroy the tourist industry.

"You can't clean up the town if you don't have everyone on board. Bars should not serve these people.

"Some hotels advertise for stag and hen parties, but others still target the family market. There is no room for both."