A Burundi UN peacekeeper has been killed in an ambush in the Central African Republic, the UN's MINUSCA mission announced on Friday.The ambush, believed to be by so-called "anti-balaka" vigilantes, occurred on Thursday evening around 20km from the town of Alindao in the centre of the country, MINUSCA said in a statement. Armed men had "attacked MINUSCA personnel who had been assuring the safety of a vehicle belonging to a contractor of the mission," the statement said. "Blue helmets had been sent as reinforcements... and it was here that they were ambushed by another anti-balaka group," it said. The incident brings the total number of blue helmets killed in the CAR this year to five. On August 18, three peacekeepers were injured in an anti-balaka attack in Mbres in the centre of the country. Two days later, other blue helmets were fired at by members of the armed rebel FPRC group in Bria, in the east. One of Africa's poorest countries, the CAR descended into violence in 2013 following the ouster of the majority-Christian country's president, Francois Bozize, by a coalition of Muslim-majority rebel groups called the Seleka.In response, Christians, who account for about 80 percent of the population, organised vigilante units dubbed "anti-balaka".* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.