Four cannisters of hazardous chemicals have washed up on Norfolk beaches over the last month.

Blue containers with a sulphuric acid hazard warning stickers were found at Hunstanton and Holme.

They were inspected by coastguards before being disposed of by the Norfolk fire service.

A coastguard spokesman said: 'Unfortunately the source is unknown and we don't know why they are being washed up on Norfolk beaches.

'We know the containers are 25L and advise any member of the public not to touch any barrels or anything suspicious that gets washed up on the shores. Dial 999 and ask for the coastguard and we will contact the relevant authority to do clean up.'

Sulphuric acid is most commonly used to produce fertiliser, although it is not known where the barrels were beign taken to or whether they were simply dumped at sea or in one of our rivers.

David North, People and Wildlife Team at Norfolk Wildlife trust said: 'Chemicals which wash up on our beaches potentially pose a threat to both wildlife and people. Visitors to beaches should always be extremely cautious about touching containers or bottles which may contain fluids or chemicals. If in doubt, they should contact the Coastguard by calling 999. Sadly, incidents of this nature are all too common and show the need to work towards less polluted seas.'

If not disposed of correctly, sulphuric acid is extremely dangerous to humans and is capable of corroding skin and if it makes direct contact with the eyes, can cause permanent blindness.

A Norfolk Fire and Rescue spokesman said: 'One 25L drum was washed up Thursday, October 25.

'There is no danger to people or animals and the drum was sealed when it washed up. Sulphuric acid is commonly used for household cleaning and can be bought over the counter.

'The drum was left with the owner of the land nearby, and the Environment Agency will arrange disposal. It is not understood where the drum came from at this point.'