Thousands of protesters have taken to the streets of Brussels to rally against a UN pact on migration.<br />Footage from Sunday's demonstrations showed police using water cannons and tear gas to disperse crowds near the European Commission.<br />Police said some five and a half thousands people took part in the larger rally, which was organized by Flemish right-wing parties who oppose the deal.<br />A smaller counter-protest by left-wing groups was attended by about a thousand people.<br />The pact is due to be approved later this week and is aimed at improving the treatment of migrants.<br />The U.S. and some European nations have rejected it, saying it could increase immigration. <br />