Police are planning a major security operation to prevent any trouble in Belfast.
Loyalist protesters opposed to new restrictions on flying the Union flag are expected to stage a demonstration in the city centre from about 1pm.
PSNI Assistant Chief Constable Will Kerr said: "We would urge those involved in the protests, to which they have a legitimate right, to take a step back and stay out of the city centre tomorrow. The risk to the public safety of all of those involved is simply too great."
He continued "The PSNI will provide a very strong presence ... over the weekend. High visibility police officers will be on the ground in Belfast city centre to assist in creating a safe environment for everyone."
Violence has erupted in towns across Northern Ireland this week after loyalists took to the streets to vent their anger.
Alliance Party offices were burnt during riots in Carrickfergus; Belfast councillor Laura McNamee was advised not to return to her home in the east of the city after threats were made against her on social media websites and the home of two councillors in Bangor, Co Down was also attacked.
ACC Kerr said: "We are aware of the ongoing tensions within communities regarding the flying of the Union flag at Belfast City Hall. People have a legitimate and democratic right to peacefully protest in relation to this issue.
"However, events across Northern Ireland over the past few days have also shown that a small minority of people will use these protests to engage in violence and disorder. This is unacceptable and does not reflect the wishes of the vast majority of all communities in Northern Ireland who simply want to enjoy the Christmas period with friends and families in peace."