PSNI Assistant Chief Constable Will Kerr appealed for calm as the Belfast protest over Union flag restrictions passed into the evening without major incident.
Earlier a driving school car was set alight in the east of the city and a policeman injured in a separate incident was taken to hospital. A 15-year-old youth and a 32-year-old man were arrested during the protest, police said.
ACC Kerr said: "Those involved in the protest should reflect on their own responsibility for any associated disorder and violence. I am appealing for calm as the day progresses. There have been too many nights of disorder across Northern Ireland and now is the time to move forward."
More top news
A court has ruled that the original coffin in which Lee Harvey Oswald was buried belongs to his brother, not the undertaker's that sold it.
Manic Street Preachers lyricist went missing nearly 20 years ago but mystery still surrounds exactly what happened to him.
Deputy Prime Minister admitted he wanted to hit David Cameron on more than 20 occasions on late-night chat show 'The Last Leg'.