Angry workers have burned down a state office in northern Mauritania, eyewitnesses reported, amid growing anger at failed negotiations between trade unions and bosses. Labourers destroyed the state headquarters in Azwirat, 680 kilometres north of the capital Nouakchott, after an unlicensed protest swept through the city streets. Other protesters invaded the state-run radio station inside, destroying satellite equipment on the roof before burning the building. Shops and schools were closed as police used sound bombs, water cannons and tear gas to disperse crowds. Negotiations between the National Company for Industry and Mines (SNIM) and unions broke down recently, a perceived reason for the anger.