United Utilities have issued advice about swimming in reservoirs, with a stark warning to 'not be the one who watches their mate drown this summer'.

The statement comes after a group of young children were spotted playing around the Spade Mill reservoirs in the Longridge area.

Bosses at the water company are now asking people to stay out of the water at their 180 reservoirs across the North West.

A statement on their website read: "Not everyone knows reservoirs are dangerous.

"Reservoirs may look inviting, especially on a hot day, but they are about the worst possible places to take a swim.

"The water never really gets above 11°C, there’s hidden machinery and there’s no lifeguard on duty.

"Not many people know that if they jump in, they won’t be able to get out.

"That they won’t be able to breathe. That they won’t be able to scream.

"And that there’ll be no one coming to save them.

"But if you did know, you might think twice about letting your mates take the plunge.

"Because none of us want to be the one who let our mate jump in.

"The one who couldn’t do anything to help.

"The one who had to stand there and watch them drown."

United Utilities say that while reservoirs are beautiful and they would encourage people to visit, they can be deadly.

Just two weeks ago an investigation was launched after a man in his 20s was thought to have drowned in the Ogden Reservoir in Barley.

Emergency services were involved in a four-hour search of the reservoir after receiving reports that a young man had entered the water and may have got into difficulties, just before 5pm on July 7.

Helicopters from Lancashire Police and the North West Ambulance Service (NWAS) were deployed, alongside a Lancashire Fire and Rescue Service drone.

Rossendale and Pendle Mountain Rescue Service also assisted with the search, which ended in tragedy at around 9pm with the discovery of a body in the water.

In June 2014, 17-year-old James Goodship drowned in Foulridge Reservoir while he had been swimming with friends.

Last month throw lines and safety signs were installed at the reservoir to warn people of the dangers of entering the deep water.

More advice along with videos that explain the risks can be viewed at unitedutilities.com/about-us/recreation-sites/reservoir-safety/