Police in Northern Ireland are mounting a major security operation for tomorrow's Twelfth of July parades amid fears of new trouble on the streets.

There were a series of disturbances in loyalist areas of east Antrim over the weekend, with further violence reported in the early hours of this morning in the Dundonald area of east Belfast.

Thousands of bandsmen and members of the Orange Order will be on the marches tomorrow.

Churchmen and senior politicians on all sides, including First Minister Peter Robinson and Deputy First Minister Martin McGuiness, have appealed for calm.

Alistair Finlay, Assistant Chief Constable of the Police Service of Northern Ireland, said today: 'Violence does not have to be inevitable,' said PSNI Assistant Chief Constable Alistair Finlay.

'People need to take responsibility to make sure everyone stays safe and secure in this tense period.'

Police claimed there was a degree of co-ordination involved in the trouble which erupted late on Saturday night and early yesterday morning in parts of Ballyclare, Carrickfergus and Newtownabbey.

Cars were hijacked and set alight and five officers were injured when one of their Land Rovers was rammed with a bus.

It followed the removal by police of loyalist flags near a Catholic Church in Ballyclare.

The biggest security operation tomorrow will be in north Belfast where Orangemen are due to march past the flashpoint republican Ardoyne district and nationalists are planning a protest demonstration.

There has been serious disorder in the area in previous years because of opposition to Orange parades.

Mr Finlay said: 'Those people with influence need to use it to keep areas calm and for heads to stay cool and to keep Northern Ireland out of the news headlines over the next few days.

'Violence does not have to be inevitable. Flags can be a difficult and emotional issue, but there is no excuse for what happened.'