Bamako - Government-allied militia forces chased Tuareg separatists from a village in Mali's troubled north after days of fighting, the United Nations mission said on Monday as it announced a safety parameter around a northern city to ensure civilian protection.At least 23 Tuareg separatists have been killed after three days of fighting with government-allied militias that broke a peace accord signed earlier this year, said Fahad Ag Mahmoud, a spokesperson for the pro-government group GATIA.Mossa Ag Attaher, a spokesperson for the main separatists Co-ordination of Azawad Movements, said some had been killed though he could not confirm the toll was that high.The UN said GATIA took over Anefis, a village that lies about 150km south of Kidal and is occupied by the separatist group, also known as CMA.On Tuesday morning a security zone of 20km will go into effect, and the UN will act accordingly if any members of government-allied militias act within the area of safety, the UN mission said in a statement. It condemned the fighting that erupted August 15 and said it was determined to protect the civilian population in the West African nation, which has also endured attacks by Islamic extremists."The growing number of violations are of great concern to the international community and the population and may hinder progress made toward a stable and lasting peace for Mali," it said.The main separatist group signed a peace accord with the government and its allied armed groups at the end of June. Government-allied groups have settled in some territory occupied by Tuareg separatists since July. Their initial presence was accepted, but separatists say their continued stay is against the terms of the accord.Both sides blamed each other for launching attacks. Mali's government called for calm.