Police and environmental groups have warned people not to swim in lakes and rivers as Norfolk is set to be scorched by the sun this weekend.

Previous hot spells have seen incidents across the county, with double drownings at Bawsey Pits in King's Lynn and Thorpe Marshes in recent years.

The incidents led to Bawsey Pits issuing a statement on its Facebook page urging people to stay out of the water and to warn others if they see anyone swimming in the quarry.

Owner Stephen Bacon also warned that there was a strict no swimming policy in place, telling people to observe warning signs.

The last 24 hours have seen three people drown in the UK, with a 12-year-old girl dying in Bury and two men pulled from the sea just off a beach in Torquay.

Norfolk police have said that local rivers can quickly cause serious problems for anyone, regardless of swimming ability, adding that changes in depth and temprature are often not noticed until it's too late.

A Norfolk police spokesman said: "Norfolk is well known for its maze of open waterways and on a hot day the water may look an inviting place to cool down.

"Please remember the rivers around the broads are unsuitable for swimming in and have hidden dangers such as a sudden change in depth, decreases in temperatures and unseen objects and currents, which can cause even the strongest of swimmers to get into difficulty very quickly."

The Environment Agency has also issued a warning to swimmers and added that last year saw 1,029 people die in accidental drownings in the UK's inland waters.

A spokesman for the Environment Agency said: "If anyone wishes to swim in a river we would encourage people to check guidance from Public Health England and the Royal Society for the Prevention of Accidents about the dangers of swimming in rivers."

New guidance issued by the Environment Agency tells those still wishing to swim in open waters to do so at recognised bathing waters and reminds people that water quality can also pose a health risk.