Five police officers have been injured during serious disturbances.
A crowd of up to 100 people attacked police with bricks and bottles at the Carnmoney Road area of Newtownabbey on the outskirts of north Belfast.
None of the officers were badly hurt.
The trouble flared just after 8.30pm.
A car was set alight and a property was also damaged.
A spokesman for the PSNI said calm had been restored to the area.
It is understood the disorder erupted after a group of men attempted to remove Irish tricolour flags from lamp posts and were challenged by the PSNI.
An office used by David Ford from the cross community Alliance Party was targeted by the rioters. A number of windows were smashed. No one was in the property at the time.
The Alliance Party has borne the brunt of anger linked to a decision to restrict the number of days the Union flag flies over Belfast City Hall.
An office belonging to another Alliance Party politician, Stewart Dickson in Carrickfergus, was destroyed by arsonists in December. The party's only MP, Naomi Long, and a number of local councillors have also received death threats.