Two teenagers who died after getting into trouble while swimming in a Norfolk broad have been named by police.
Bonheur Musungay, 14, and Stella Kambi, 17, were on a family day out at St Andrews Broad at Thorpe Marshes on the outskirts of Norwich when the tragedy happened late on Wednesday.
Norfolk Police believe Miss Kambi was trying to rescue Mr Musungay. Mr Musungay got into difficulty while swimming and Miss Kambi tried to help before getting into trouble herself, the force added.
Detective Sergeant Sarah Knights said: "This is a tragic incident and, on behalf of everyone involved, I would like to offer my condolences and deepest sympathies to the family."
She added that members of the public had entered the water before emergency services arrived, but were unable to help.
"A number of witnesses were spoken to at the scene and we will now continue to work together with partners to piece together what happened and post mortems will take place in due course," Ms Knights added.
"Without wanting to prejudge what has happened here, I would urge people to take the utmost care around water and to be aware of hidden dangers such as fast flowing currents and underwater obstacles and weeds."
Brendan Joyce, chief executive of Norfolk Wildlife Trust, said new "no swimming" signs had been put up in recent weeks, but were almost instantly ripped down in the latest in a spate of vandalism attacks.
He said: "We are all very shocked and saddened at Norfolk Wildlife Trust to learn of the tragic loss of life of two teenagers at our Thorpe Marshes Nature Reserve. Our thoughts are with family and friends.
"We are unclear as to exactly what took place that led to such very sad circumstances. We would not want to speculate, but rather await further information from the emergency services.
"We put up 'no swimming' signs around the former gravel pit, warning of the dangers of swimming in the area - but these are often vandalised and ripped down. New signs were erected as recently as Monday."
On Thursday, only one sign could be seen at the entrance to the site, almost half a mile from where the pair are thought to have entered the water. At the beach area near where they died, only one sign could be seen warning of dangerous algae.
Gordon Copp and his daughter Amy, 14, who is in the same class at Thorpe St Andrew High School as a relative of the pair who died, visited the site on Thursday.
Amy said: "This is a popular swimming spot - often kids from school will come down here and come back with wet hair. I've been worried about safety for a while and there isn't anything to stop people getting into the water."
Mr Copp, who lives nearby, allowed the family of the teenagers to sit in his garden as emergency services launched a major search to find the pair at about 4.50pm. "They were screaming and wailing and seemed in a terrible state," he said. "They seemed absolutely distraught and my heart goes out to them."
Norfolk Fire and Rescue Service, East of England Ambulance Service, search and rescue, the Coastguard and the police helicopter all helped with the search.