VE Day riots in Dublin?

From memory, it was student japes rather than riots. A group of Trinity students ran a number of flags up the flagpole over Front Gate - the Union Jack, the Soviet flag, a French tricolour and an Irish tricolour. The Irish flag was at the bottom. A number of onlookers objected vociferously to the placement of the Irish flag at the bottom and attempted to rush Front Gate, whereupon the students removed the Irish flag and burnt it. Someone then tore down a union jack from a lamppost on Grafton Street and burned that. And then it all kicked off. The guards had to draw batons to restore order. Twelve people treated at Mercer's Hospital for slight injuries.

Reportedly, it was Charlie Haughey and Seamus Sorohan, both then students at UCD, who tore down the union jack and burnt it. But this story may have grown in the telling.