UN chief Ban Ki-moon spoke with French Foreign Minister Laurent Fabius on increasing the number of European and African troops in the Central African Republic, the UN said.Ban "asked what could be done to increase support to MISCA, to accelerate the deployment of the European Union troops, and whether additional troops might be envisaged," UN spokesman Martin Nesirky said.African peacekeeping-force MISCA has already sent some 5,400 of 6,000 planned troops, and some 1,600 French soldiers are on the ground in the CAR. The EU has promised to deploy 500 troops to Bangui at the beginning of March.Nesirky added that the secretary-general "stressed that the international response must be robust enough to stop the violence and prevent what has a high potential to result in additional widespread atrocities."Ban "reiterated that the international community had a collective responsibility towards the people of the CAR" and denounced the cycle of retaliatory attacks and sectarian violence between Muslims and Christians, Nesirky said.On Monday the commander of French troops in the CAR accused a militia known as the anti-balaka of being the country's "main enemy of peace" to be treated as outlaws and thugs.The mainly Christian vigilantes have been accused of brutal attacks against Muslims after the ouster of president Francois Bozize in March 2013 by mainly Muslim rebels led by Michel Djotodia, who was himself forced out last month after failing to end the sectarian violence.