A caravan was set alight with people inside at a seaside holiday park.
The fire was reported at Cresswell Towers at about 1am on Sunday. The occupants of the van awoke and escaped unhurt, but severe damage was caused. Lit paper had also been pushed through the window of another caravan, but was extinguished before fire took hold.
Park Resorts, which runs the site, said it is co-operating with police, but had no comment. Anyone with information should call 101.