Belfast , Northern Ireland ( CNN ) -- Authorities accused pro-British extremists of exploiting protests in Northern Ireland over the Belfast City Council decision to stop a century-old tradition of flying the Union Jack year-round . The protests calling for the council to reverse its ruling over the flag continued Monday evening , police said . About 400 people gathered at Belfast City Hall as the City Council met for the first time since it voted to fly the British flag only on certain days , police said . The protest , which was mostly peaceful , was organized via social media , authorities said . In East Belfast , about 250 protestors gathered , and missiles such as petrol and paint bombs , fireworks and heavy masonry were thrown at police . Police responded with water cannon , authorities said , and overall calm had been restored Monday night . Four people , two males and two females , were arrested , accused of riot and public order violations , police said . Authorities say at least 52 officers have been wounded in protests . Read more : Fresh protests break out in Northern Ireland after night of violence . The chief constable for the Police Service of Northern Island put the blame for the violence on members of the loyalist Ulster Volunteer Force , who were `` orchestrating violence for their own selfish motives . '' The British flag , the Union Jack , has long been a flashpoint between British loyalists -- primarily Protestants -- who want to remain part of the United Kingdom and Irish nationalists calling for Northern Ireland to join Ireland . Northern Ireland 's political leaders have called for an end to the pro-British protests , and politicians , clergy and community met Sunday to discuss possible ways to bring about an end to the unrest . `` Everyone involved needs to step back . The lack of control is very worrying , '' Chief Constable Matt Baggott told CNN . `` The only answer is a political solution . '' A large number of police officers have been pulled away from their normal duties to deal with the demonstrations , Baggott said . If this continues , `` it will eat into our ability to deal with drugs , into our ability to deal with alcohol issues , and deal with what is a very severe dissident threat . '' Among the more than 70 arrested since the protests began was a 38-year-old man who was arrested Saturday on suspicion of attempted murder and being in possession of a gun . Police said that at the time of the man 's arrest , there were reports of shots being fired at police . Read more : Policewoman targeted as Northern Ireland tensions rise . The vote on the flag followed a summer of heightened tensions between Northern Ireland 's Catholic and Protestant communities . Riots in September left dozens of police officers injured . The majority of the island gained independence in 1921 , following two years of conflict . But six of the nine counties of the province of Ulster chose to stay in the United Kingdom , eventually becoming the country of Northern Ireland . In the late 1960s , the conflict between mainly Protestant loyalists , who want Northern Ireland to remain part of the United Kingdom , and largely Roman Catholic nationalists , who want it to be reunited with the rest of Ireland , exploded into a political and sectarian war , known as `` the Troubles . '' Read more : Police : Loyalist paramilitaries behind Northern Ireland violence . The three decades of ensuing violence between loyalists and the IRA claimed more than 3,000 lives , most of them north of the border . While the Good Friday Agreement of 1998 , also known as the Belfast Agreement , effectively ended the conflict , distrust remains between Catholics and Protestants . Under the terms of the accord , groups on both sides dumped their weapons , and members of Sinn Fein , the political affiliate of the IRA , now work with pro-British politicians in Northern Ireland 's power-sharing government . Read more : Clinton urges calm amid tensions in Northern Ireland . CNN 's Chelsea J. Carter contributed to this report .
Authorities accuse a loyalist extremist group of `` orchestrating violence '' The Belfast City Council meets for the first time since its controversial ruling . In December , the council voted to fly the Union Jack only on certain days . The flag is a flashpoint between those who want to remain part of the UK and those who do n't .