Homes were evacuated and three staff from the Bull Bay Hotel were hospitalised after a chemical - suspected to be phosphorus lifted from a wreck by divers - ignited in the road at Amlwch, Anglesey.

The toxic alert started after the Head Chef at the Bull Bay Hotel saw smoke rising from the road outside. A smouldering chemical lump ignited, despite the repeated attempts of staff from the hotel to extinguish it. The hotel and several homes were evacuated by police while pollution control officers from the Environment Agency assisted the fire brigade in dealing with the chemical.

The three people who tackled the blaze were sent to hospital for preventative treatment for chemical burns; their clothing was destroyed. Fortunately no injuries were sustained.

Bull Bay is a popular dive site, offering a usable slip for launching small boats, and the Bay area is used by many for diver training. However, several of the deeper wrecks are known to contain munitions, and it is not the first time that divers have caused an incident by removing phosporus - which ignites and burns in air - from the wrecks. The wreck of the Cork, in 37m, just outside Bull Bay is known to contain phosphorus and munitions.

Underwater, phosphorus has a blueish grey, waxy appearance and can resemble a lump of cheese or roughly hewn marble. Divers have been known to pick it up and bring it back without realising the danger that it poses.

The Coastguard issue the following advice to divers: