Police are stepping up patrols along the Kennet and Avon Canal after vandals set fire to a beauty spot in Trowbridge.

The vandals broke fencing, and used the wood as fuel for the fire which destroyed the base of an old lock post.

They left cans of alcohol and dumped a plaque marking Balls Bridge, which is next to the site at the rear of the Airsprung factory in Canal Road.

The fire is believed to have started on Sunday and firefighters were called out at 7.30am the following day.

The crew extinguished the blaze and informed police.

Ranger Richard Craft, who tends the canal path, said: “We were absolutely horrified.

“We had only just repaired the fencing two weeks ago and they have taken away the posts and put them on the fire.

“It just makes you wonder why they do it. Lots of people use this area because it is so nice.

“We have worked very hard over the years to get it to what it is now and people enjoy sitting on the bench here.

“The problem is that the area is quite remote and in the evening youths can roam free because there are no houses nearby.”

Mr Craft is part of a team from Sustrans, a charity which has set up a national network of cycleways, including one along the canal.

About five years ago Sustrans were handed a £3,000 grant from British Waterways to improve the area, but work has been plagued by frequent vandalism.

Sergeant Chris Hams, of Wiltshire Police, said: “Clearly a huge amount of money has been spent on the canal and a lot of volunteer work has taken place.

“This is just a mindless act of vandalism and we will be pulling out all the stops to catch the offenders. I would urge anyone that can help us to get in touch so we can protect this beauty spot.”

Police are asking witnesses to contact them on 0845 408 7000.