A major security operation is being prepared for today's big Twelfth of July parades in the North in the aftermath of weekend disturbances in loyalist areas of east Antrim.
Churchmen and senior politicians on all sides, including First Minister Peter Robinson and Deputy First Minister Martin McGuinness, have appealed for calm.
Police claimed there was a degree of co-ordination involved in the trouble which erupted late on Saturday night and early Sunday morning in parts of Ballyclare, Carrickfergus and Newtownabbey.
Cars were hijacked and set alight and five officers were injured.
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 to carry out a protest demonstration.
There has been serious disorder in the area in previous years.