CHURCHES are the latest targets of "nighthawks", a name given to those who use metal detectors under cover of darkness to dig up and steal archaeological artefacts.

The Grade I listed chapel of St Peter-on-the-Wall, in Bradwell-on-Sea, Essex, has been repeatedly targeted by nighthawks, who have dug holes around the site looking for treasure. The chapel, a place of pilgrimage associated with St Cedd, dates from AD 654.

The police have set up a dedicated team of officers to deal with the problem. Operation Chronos is a national campaign, led by Essex police, to target unlawful metal detectors, and is supported by Historic England. It says that there have been about 140 cases of nighthawking over the past five years, and, far from working alone, the metal detectors operate in gangs, and have sophisticated equipment.

Stolen items are often kept in private collections, or sold on auction websites. The goods are difficult to trace, as the existence of the artefacts are unknown when they are stolen.

Ecclesiastical Insurance, which insures the majority of churches in Britain, said that it had not had any claims in relation to treasure-hunters, but it advised churches to improve security lighting around their grounds to deter thieves.