Cruel hooligans are subjecting swans to a summer of violence, a wildlife campaigner has claimed.

Trevor Weeks, of the East Sussex Wildlife Rescue and Ambulance Service, has been left horrified and sickened by a series of attacks across Sussex.

Swans at different locations have been injured and killed after coming under assault by gangs.

Mr Weeks said: "In the past 18 years undertaking wildlife rescue work, I have never experienced such brutality and mindless aggression towards wildlife as we are experiencing this year."

Up to seven baby swans, who had been living in the River Ouse in Lewes, were killed last month in a suspected stone-throwing attack.

Colin Stapleton, who runs a nearby butchers' store, was so upset he put up a £1,000 reward for the arrest and conviction of the killers.

But only a few clues have emerged and no arrests have been made.

More recently, a swan died at Langney Pond, near Eastbourne, after swallowing a fishing hook.

It caused an abscess which closed the bird's windpipe.

Mr Weeks said youths had been regularly spotted hurling stones and sticks at swans in Princess Park, Eastbourne.

He said: "Their most recent form of attack is to use a piece of wood with string and a large hook which they throw at the swans to try to catch them. Why?"

A female swan died after being attacked by a large dog in Egerton Park, Bexhill, last Sunday.

A dog owner has been charged by police with being in charge of a dog that was out of control in a public place.

Mr Weeks said the family of the swan which was killed had recently been the target of people throwing stones and missiles.

He said: "My parents both worked on farms and I was brought up to respect animals and appreciate them and the environment they live in.

"It is a shame youths these days are not taught the same.

"Why does anyone feel the need to inflict pain and suffering on any living creature, especially on a bird as elegant and majestic as the mute swan?"

He suggested more should be done to protect swans, including the use of mesh screens, fences or CCTV cameras.

His group, made up of volunteers, has a turnover of £9,000, all raised through donations and charity events.

His teams were involved in almost 4,000 rescues last year.

He said: "This year, since the nesting season began in March, we've had to put so many more resources into rescuing and protecting swans and it is a struggle to keep going."