BNPS.co.uk (01202 558833)
Pic: DorsetPolice/BNPS

Pictured: Police are using an all-terrain vehicle to patrol the area.

Police have stepped up patrols of a protected heathland after a series of 'deliberate' fires started by youths threatened nearby properties.

Since April 1 there have been 21 fires at Bourne Valley Nature Reserve in Poole, Dorset.

Recent fires have been creeping closer and closer to properties and playgrounds surrounding the open space.