NICOSIA -- Activists prevented British groundwork starting on a controverial antenna site in Cyprus on Monday which locals fear is a health and environmental risk.

Around 20 activists camped overnight to prevent heavy machinery entering a site earmarked for new aerial masts close to Raf Akrotiri, a sprawling British military base on the southern coast of Cyprus.

"There are health concerns, and an international panel of experts has said this work could cause irrevocable environmental damage," MP George Perdikis of the Greens Party told Reuters.

Similar attempts by the British bases to start work on new communications masts triggered unprecedented violent protests in the area exactly one year ago.

Cyprus's Parliament has expressed its opposition to the creation of new masts.

Britain has two military bases on Cyprus which it has held onto since granting the east Mediterranean island independence in 1960.

The bases say the masts, in an area it has sovereignty over, are needed for its global communications network.

Rob need, a spokesman for the bases, said experts were to start removing wildlife from the earmarked site and transfer it to another region in a bid to minimalize the impact on the area, which is a salt marsh.

"Work on the masts themselves is not due to start until next year," Reuters reported.