DAKAR (Reuters) - Militia violence in Central African Republic has killed around 300 people and displaced 100,000 in the last two weeks, the United Nations and the government said on Thursday, in the worst displacement since a 2013 civil war.

The violence marks a sharp escalation in the long conflict that began when the mostly Muslim Seleka rebel coalition overthrew then-president Francois Bozize in 2013, prompting reprisals from Christian anti-balaka militias.

Fighting in the last two weeks has hit the towns of Bria, Bangassou and Alindao, all hundreds of kilometres east of the capital Bangui, the U.N. humanitarian office and the minister of social affairs said in a joint statement.

“It’s a catastrophe,” Social Affairs Minister Virginie Baikoua told journalists after a visit on Wednesday to Bria. “Houses are burnt down, others pillaged ... The displaced are afraid it could degenerate at any moment because armed men are roaming around the camps.”

More than 41,400 of Bria’s 47,500 inhabitants were displaced by fighting between May 15 and 18, the statement said.

The Red Cross said last week it had found 115 bodies in Bangassou, a diamond-mining area on the border with Democratic Republic of Congo after it was seized by hundreds of militia with heavy weaponry.[nL8N1IJ332]

U.N. peacekeepers, part of a 13,000-strong force, have since secured Bangassou and reinforced their positions in other areas, the mission (MINUSCA) said in a statement.

Around 440,000 people were displaced throughout the country by the end of April and that number could reach 500,000 by the end of May. That would represent the most displaced since the height of the crisis in 2013, the U.N. humanitarian office said.