SECURITY has been stepped up after hundreds of youngsters were caught trespassing and illegally swimming at Tytherington Quarry over the past two weeks - putting their lives at risk.

Guards have been posted at North Face Quarry, one of three quarries in the village, and new signs warning swimmers of the dangers of diving in its deep waters have been placed around the mothballed industrial site.

Damaged fencing has been replaced around the quarry to stop intruders.

But the emergency measures have done little to deter the swathes of young people determined to get in.

With the start of the school holidays, an increasing number of them have been sneaking in the quarry. On Sunday, nearly 50 young people unfazed by the two security guards made their way to the quarry to fend off the heatwave.

The previous weekend, police had to intervene after 40 people got onto the site, swimming and having picnics by the water.

As the Gazette spoke to North Face Quarry site supervisor Aziz Shamsul Huda on Monday, another group of youngsters had just slipped through the fence.

"It's only just beginning," he said. "The water is 30ft deep in the middle. It's very cold; if someone had cramp in the middle of the quarry they would end up sinking. And there are the cliff edges. It's not safe."

Local neighbourhood Sergeant Steve Davey said police had been called several times to the quarry over the past few days.

"Swimming in quarries, or any unsupervised water, simply isn't safe," he said. "You can't see what debris is beneath the surface, don't know how strong the current is, and can't judge the impact the very cold temperature of the water will have on your body.

"Often, especially with quarries, the water is exceptionally cold, which can cause even the best swimmers to get cramp, go into shock and drown quickly."

Hanson Aggregates, which owns one of the three quarries in Tytherington, teamed up with North Face Quarry owners FCC Environment to protect the community.

A Hanson Aggregates spokesman said: "We want to make sure young people are safe. We want the dangers of swimming to be explained to them. That's why we are going to great lengths to repair the fencing. We've had to take action quickly."

He added: "It looks attractive and a wonderful place to be but it's not. The reason we are concerned the young people are in the quarry at the weekends and in the evenings is there's nobody who could get in there and help them."

Both firms are worried about messages posted on Facebook encouraging large groups to take a refreshing dip in the quarry. They were due to meet this week to discuss further safety measures.