STAFF have been placed on alert after a group of youngsters tried to disrupt a carol service.

The group ran amok outside Ripon Cathedral, North Yorkshire, letting out cat-calls and noises aimed at spoiling the service.

The cathedral has suffered from vandalism, petty thieving, interruptions to services and intimidation of worshippers during the past 18 months.

Organist and master of choristers Kerry Beaumont blamed a minority - usually aged between 13 and 15 - for the outbursts.

However, the troublemakers are often drowned out by a packed congregation, combined choirs and the organ.

Mr Beaumont said that unlike York Minister, the cathedral did not have its own police force and had to rely on staff and vergers to control anti-social behaviour.

Clarry Pawson, head of the cathedral's Select Vestry, said vergers would now be on alert over the festive season, particularly on New Year's Eve when there have been problems in the past.

Mr Beaumont said the situation had improved recently after a message went out that vergers had been equipped with cameras to "snap" culprits. "But I am afraid it might get worse before it gets better," he said.

Mr Pawson said they had a "quick line" to the police in a bid to stem problems. But staff acknowledged that it was difficult to catch those responsible.

Following previous outbursts, some of them inside the building when foul and abusive language has been used, North Yorkshire Police announced a change in policy to the problem.

Instead of being warned in front of their parents, culprits would be prosecuted. Girls as well as boys have been spotted as troublemakers.

The worst recent incident inside the building came when the Saxon crypt suffered a graffiti attack.