A 14-year-old boy is missing and is believed to have drowned after getting into difficulty in the Thames.

Police were called at just after 4.30pm today after being alerted by the London Ambulance Service to reports that a child had been seen to enter the water at Tagg's Island in Hampton.

Officers responded with paramedics and the London Fire Brigade.

Earlier today, the RNLI and the police had issued warnings to youngsters and others against jumping into the Thames. They issued warnings about the impact of cold water shock and said there were also dangers about colliding with objects hidden beneath the surface.

Richmond Police said: "Tragically, a 14-year-old boy has drowned after getting into difficulty in the Thames earlier. Our thoughts are with his family.

"It's a very real reminder of how dangerous open water can be. Please listen to the warnings and encourage others to do so too."

The Metropolitan Police said: "An extensive search was carried out involving all three emergency services and members of the public.

"Very sadly, efforts to locate the boy were unsuccessful and at 18:40hrs, the rescue operation was brought to an end. Efforts to recover his body will continue into this evening.

"His next of kin are aware and are being supported by specialist officers."

Superintendent Richard Smith, from the South West Command Unit, said: "Despite the very best efforts of all involved, we must now sadly conclude that this young boy has died.

"His death is a tragedy and I cannot begin to imagine what his family will be going through. All our thoughts are with them.

"I know that on days like today when temperatures are at a record high, it might look appealing to jump in and cool off in rivers, reservoirs, lakes or other open water.

"Please don't. The dangers are real and this evening in Richmond we have seen the terrible consequences of what happens when it goes wrong.

"To young people in particular, I would urge you to be the person in your group of friends who says no and reminds others about the dangers.

"Your intervention could save a life and save another family from experiencing such an awful loss."