1 July 2012 Last updated at 06:56 ET

11 walkers talked off Snowdon after group lost in mist

Mountain rescuers talked down the group lost in mist on Crib Goch, seen here behind Llyn Cwmfynnon, by phone

Large groups of walkers are taking to Snowdonia's mountains without the right clothing for the weather, say rescuers.

John Grisdale, Llanberis Mountain Rescue Team chairman, said a group of 11 was talked down from Snowdon on Saturday evening after becoming lost in mist.

He said: "The bigger the group the more likely they are to get split up."

It was the third incident of the day, with a man and teenager brought down off the slopes in separate incidents.

Mr Grisdale said a team of five rescuers was called to the first incident, a man in his 30s who had fallen at Llanberis Pass, shortly after 13:00 BST.

But as the rescue team were travelling up on the mountain railway they had to split up after learning a 15-year-old boy on the Pyg track had a suspected broken ankle.

The first group helped the injured man to the mountain railway and then linked up with the second team helping the teenager.

They were in turn aided by members of Aberglasyn mountain rescue team who were then called away to an incident of their own, said Mr Grisdale.

As the Llanberis team were returning, they were called to help the party of 11 lost on Crib Goch ridge.

Mr Grisdale said: "They were talked down off the hill by phone. They found their way down to the Pyg track.

'T-shirts and jeans'

"In the course of six hours we dealt with three separate incidents.

"It's hardly surprising. The pressure of people on the mountain is extremely high.

"There are now often large groups of people on the mountain, including sponsored walks.

"Many of them are poorly equipped for the conditions.

"We have come across organised groups who are going up in T-shirts and jeans rather than supporting best practice.

"There are some that have best practices but some have a lack of understanding of the mountain conditions which at this time of the year can still be cold and wet.

3am at summit

"They need to be better prepared for the weather, with winds and lots of rain. The temperature is quite low as well.

"Being prepared is a significant part."

Mr Grisdale added that early on Sunday morning a man taking part in a Three Peaks Challenge sparked an alert after he became separated from his party shortly the group of three reached the summit of Snowdon at around 03:00 BST.

The man eventually made his own way down to Llanberis and notified the authorities at around 08:00 BST, he said.