Bamako - At least 20 people were killed during violent clashes between two Tuareg rebel groups in northern Mali, the military said on Saturday.
Rebels from the separatist National Movement of the Liberation of Azawad clashed with fighters of the Arab Movement of the Azawad Friday in the northern town of Anefis, military sources told dpa on the condition of anonymity.
The Malian government and separatist rebels agreed to a ceasefire in May. "Some armed groups do not respect the ceasefire agreement.
This is an issue of great concern", the UN peacekeeping chief Herve Ladsous said after visiting the northern city of Gao.
The impoverished West African country is recovering from a 2012 military coup that gave Tuareg separatists and later militants associated with al-Qaeda control of the country's north.
French and African military forces joined the Malian army in dispersing the militants and restoring government control, but terrorist activities and military operations still continue in some areas.