A bunker used to store straw and hay was set alight by arsonists at New Ground on Portland, firefighters said.

A Dorset Fire and Rescue Service spokesman said crews from the island were called to the bunker measuring 8m x 20m near the High Angle Battery at 4.50pm on Sunday.

They extinguished the blaze using two breathing apparatus sets, hose reel lines and a main line and said they believed it had been started maliciously.

The two crews left at 7.30pm but returned at 9.30pm to re-inspect the area and check it was safe.

Fire damage was caused to two of the rooms with smoke affecting the rest of the bunker.