A video released on YouTube appears to show people among St Patrick's Day revellers in Belfast city centre shouting pro-IRA chants.
The video shows revellers standing on Donegall Place and Royal Avenue when chants of 'the IRA' can be heard for around eight seconds.
At Belfast City Hall loyalists held a Union flag protest, draping Union flags over the gates of the building.
The loyalist protest stems from December 2012 when Belfast councillors voted to switch from permanent displays of the Union flag at City Hall to designated days.
Around six PSNI Land Rovers lined the middle of the road to separate the protesters and young people celebrating St Patrick's Day - many of whom were draped in Tricolour flags.
Anon Ireland captures PSNI RUC brutality on Irish youths in Belfast for singing and chanting Irish Republican songs. While loyalists jeer and cheer them on.Posted by Anonymous Ireland on Thursday, 17 March 2016