The damage was caused overnight on Sunday, with about 40 of the 280 plots in Kingsley Park allotments affected.

Three steel poles were pushed out of a security fence by the burglars as a way into the grounds. They then trashed the plots before apparently trying to make off with a lawn mower, which was found abandoned about 100 yards away from its shed.

Chairman of Kingsley Park Allotments Association, Tony Stevens, said the attack was very upsetting for the members, many of whom had rented plots at the site for several decades.

He said: "It is such a shame for people.

"A lot of them spend all day up here and put a lot into their plots, so this is their life. We have a great community up here and this sort of mindless vandalism is just such a nuisance.

"It's also the hassle and expense of replacing locks and windows which is very annoying. The trouble is that it's impossible to completely secure wooden sheds."

Many of the allotments are owned by pensioners, with some in their 90s who visit the grounds each day.

Treasurer of the allotment association, Pat Pitt, has three plots at the grounds which were all vandalised.

She said: "It doesn't look like they have stolen anything but that's not really the point. It's just really unfair to people who spend most of their time at the allotments and who don't have much else, and now they've got to pay for the repairs.

"They tried to get away with my lawn mower but we found it abandoned two plots over, but they were determined to get in. It can't have been easy to break through the security fence.

"We have had some trouble here before but nothing like this, and it's been fairly quiet recently."

Anyone with information about the vandalism can call police on 08453 700700.