After a fourth night of violence in Belfast, the chief constable of Northern Ireland's police has been speaking out against the riots.
Matt Baggott said there was "no excuse whatsoever" for violence.
He confirmed that since the protests began, 96 people have been arrested, including many young people.
Mr Baggot said he was very worried that children as young as 10 were becoming involved.
The protests are taking place because of a decision by Belfast City Council to change how often the union flag is flown over Belfast City Hall.
Most protests have been peaceful, but some have turned violent.
On Sunday night, bricks, barriers and bottles were thrown at police, as hundreds of protestors walked up one of the city's main streets.
The union flag represents Northern Ireland being part of the United Kingdom, something not everyone living there is happy about.
Nationalists - who think Northern Ireland should be a part of the Republic of Ireland - wanted the flag to be taken down completely from Belfast City Hall. But they agreed for it to be flown on special occasions.
The result angered loyalists - they want to stay part of the UK and want the flag flown all year round.
Politicians in Belfast and London have condemned the violence.
For more information check out our guide to Northern Ireland.