What seems like a harmless summer pastime could result in a young person being crushed to death, an expert has warned.

As temperatures soar, sun-seekers young and old have been enjoying relaxing afternoons at the City Road basin, but Ian Shacklock, chair of the friends of Regent’s Canal, says some teens could be putting their lives in danger.

Some young people have been seen running along the top of the lock gates – even jumping from one beam to another – while the friends open and close the contraptions which could be potential death traps.

Mr Shacklock said: “It’s deceptive how dangerous it is. Youngsters are opening and closing these gates while their friends are walking or jumping across them.

“If one of them slipped into the water and the one pushing the gate panicked and let go, the gate would swing shut and trap them between the gate and the canal wall. They could be crushed to death.

“There is no reason on earth for anyone who hasn’t got a boat and isn’t properly trained to be using these gates.

“The Canal and River Trust (CRT) should put up notices.

“All it takes is for someone to slip and we could have a fatality – a senseless accident.”

Cllr Klute, who represents Islington’s St Peter’s ward, which covers the lock, said: “Signs are needed but this is symptomatic of a bigger problem – the CRT’s inability to enforce their rules and regulations. The canal and towpaths are becoming increasingly lawless.

“Boats are outstaying their licences and one person was blasting music and selling unlicensed alcohol from his boat. And teenagers have been climbing on to the cafe roof and exposing themselves. The CRT need to shape up a lot.”

A 50-year-old man whose house overlooks the basin and asked not to be named, said: “It’s hell living here at the moment. The kids treat the canal like their personal swimming pool. They spend all day dive bombing, trying to splash people, spitting and shouting abuse. The CRT really need to take responsibility.”

A boat owner who wished only to be known as Aarron M said: “This happens every year during the summer holidays and no one ever engages these kids.

“They aren’t going to take any notice of signs – they need to be educated about the dangers of the canal - as does the whole community.”

Jon Guest, London waterway manager at the CRT, said: “Locks can be dangerous places if they’re not treated carefully: the water is very deep and the gates are very heavy. We are talking to the café about putting temporary signs up at City Road Basin and we would like to find a volunteer lock keeper for Islington, who would be able to tell people how to use the locks properly.

“If you think someone is putting themselves or others in danger, please contact the police to let them know. We urge people not to swim in the canal and to use the locks sensibly – there are plenty of ways to enjoy the waterways without putting yourself at risk.”