The Union flag will fly over Belfast's City Hall today to mark a royal birthday.
But loyalists are expected to stage a protest as the flag is hoisted for the second time since city councillors voted to restrict the number of days it can be raised to 18.
The flag will be raised to mark the 48th birthday of the Earl of Wessex's wife Sophie.
On Saturday night a man and two teenage boys were arrested in east Belfast during protests over the flag controversy.
The 30-year-old man was arrested on the lower Newtownards Road on suspicion of disorderly behaviour and provocative conduct.
Earlier there was a heavy police presence as hundreds of people attended a peaceful demonstration at the city hall.
Loyalist paramilitary chiefs in east Belfast, community leaders and clergy this week called for an end to the violence which has dogged parts of Northern Ireland since December 3.
More than 100 police officers have been injured since the disorder began.