Police have arrested nine men and two women as loyalists staged more protests over the decision to restrict the flying of the Union flag at Belfast City Hall.
Three men were detained on suspicion of a number of offences including disorderly behaviour and obstructing a highway following a protest in the Waterside area of Londonderry.
In Belfast six men and two women were arrested on suspicion of obstructing a highway following a protest on the Knock dual carriageway area in east Belfast, according to the PSNI.
The protests are now into the eighth week after city councillors in Belfast voted to fly the flag on designated only days.
There was already traffic chaos in various parts of Northern Ireland because of heavy snowfalls which left dozens of roads in a treacherous condition.
There were other protests in Antrim, Ballyclare and Carrickfergus and the coastal road outside the village of Glenarm, Co Antrim.