ANTOINE ROLLAND THREEE United Nations peacekeepers have been killed in the Central African Republic, the U.N. mission there has announced, as the government and its allies tried to fend off a rebel offensive ahead of Sunday's presidential and legislative elections. The Burundian peacekeepers were killed by unidentified assailants in Dekoa, about 200 km (125 miles) north of the capital Bangui, according to the U.N. mission, known as MINUSCA. Two more were injured, it said. Peacekeepers were also attacked by unknown assailants in Bakouma in the southwest of the country, MINUSCA added. The Central African Republic, which is rich in diamonds,…