Loyalist protestors threw a number of missiles including plastic bottles and fireworks as the bands and up to 4,000 participants made their way along Royal Avenue on Sunday afternoon.Both sides exchanged verbal abuse.One member of the public and one police officer were injured during what the PSNI described as "minor trouble" in city centre, as police in riot gear stood between protestors and marchers.Assistant Chief Constable Mark Hamilton said: "Our focus was, as always, on keeping people safe."Police will now review all evidence gathered and pursue all relevant lines of inquiry relating to any offences or breaches of the Parades Commission determinations."The PSNI mounted a major security operation ahead of the Anti-Internment League parade, which marked the anniversary of the introduction of detention without trial in Northern Ireland in 1971.There was trouble at the same event last year when loyalist protestors clashed with police, injuring dozens of PSNI officers during severe rioting on a Friday evening.A loyalist protest took place at the junction of Royal Avenue and Lower Garfield Street on Sunday, but had been restricted to 200 protestors.The parade passed off largely without incident.Mark Hamilton continued: "Today's parade and associated protests passed off with minor trouble, with a number of fireworks and missiles thrown as the parade passed through Royal Avenue. One officer and one member of the public are reported to have each sustained a minor injury."There was a considerable policing operation put in place throughout the city centre today to ensure that the Parades Commission determinations were upheld."The parade was supposed to make its way into the centre of Belfast at 1pm from the Ardoyne area, but the start was slightly delayed due to bad weather conditions.Dozens of police in riot gear lined the route to keep groups apart, while metal security fences were set up throughout the city centre. A water cannon was also on standby.A number of diversions were in place around Belfast to facilitate the parade and protests, causing some traffic disruption, with motorists asked to avoid many areas.The area was reopened again to Sunday shoppers shortly after the parade passed.Willie Frazer, who was at the protest, said missiles should not have been thrown, but claimed some of those involved in the march had been shouting about IRA atrocities.He said: "The parade is a total disgrace."I know there were missiles fired, that should not have happened, but if people listen to what they were shouting, they were shouting about Kingsmill, the Shankill bomb and Teebane."These are the people who say they want to move on and get on with our communities."The parade took place in the wake of Saturday's peaceful Apprentice Boys marches in Londonderry which police had described as "exemplary".Chief Constable George Hamilton tweeted that he hoped Belfast could mirror this success.Two arrests were made in Londonderry on Saturday however police said events had taken place largely peacefully for the third year in a row, due to the hard work of many local agencies.Chief Superintendent Stephen Cargin said: "Yesterday's Apprentice Boys of Derry parade in the city passed off extremely well, the parade itself was exemplary."I am pleased to say that I can't remember a parade that has gone so well in the 28 years that I have been policing in this city and I hope that this positive momentum only continues."