ARSONISTS set fire to a derelict building at North Site, in Malvern, after cutting a hole in the security fence.

The blaze at the former Ministry of Defence base took 25 firefighters four hours to put out and could be seen from as far away as Worcester.

Security staff from Persimmon Homes, which now owns the land off Leigh Sinton Road, saw the fence had been damaged but were too late to stop the intruders setting the three-storey building alight.

Firefighters from Malvern, Worcester and Bromyard tackled the blaze after the alarm was raised at around 9pm on Thursday, May 26.

"It was a big fire. The smoke and flames could be seen from seven miles away," said Alec Mackie, of Hereford and Worcester's Fire and Rescue Service.

"The roof collapsed while the firefighters were there but no-one was hurt."

Mr Mackie said the building was very badly damaged, with the roof completely destroyed and the walls now unsafe.

The intruders are believed to have gained access by cutting a hole in the fence where the site boundary follows a public footpath, just off Sayers Avenue.

A spokesman for Persimmon, which bought the site in March and plans to build 390 houses there, said: "The 12ft-high perimeter fence was vandalised and, although quickly noticed by our security guards, the trespassers started a fire in one of the disused buildings.

"Our security staff contacted the fire brigade, who quickly brought the fire under control before it spread to other buildings.

"Persimmon Homes would like to thank the fire brigade for their prompt response and are co-operating with the police in their investigation."

A spokesman for Malvern Hills police said the building was too dangerous for its scenes of crime investigators to get inside.