Bamako, Ramadan 15, 1435, Jul 12, 2014, SPA -- At least 20 people were killed during violent clashes between two Tuareg rebel groups in northern Mali, the military said Saturday. Rebels from the separatist National Movement of the Liberation of Azawad clashed with fighters of the 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," UN peacekeeping chief Herve Ladsous said after visiting the northern city of Gao. --SPA 15:08 LOCAL TIME 12:08 GMT www.spa.gov.sa/w