The brother of a radio host who was shot and killed along with two others outside a Christian radio station in Mali's Timbuktu says authorities have arrested two people in connection with the shooting.

Chekou Dicko said Monday that the gendarmerie called him to say two suspects had been arrested and were being questioned. Chekou is the older brother of Joel Dicko, the radio host who was killed.

Witnesses say a gunman on Dec. 17 shot the radio host, a local contractor with the U.N. and a student before fleeing.

Mali's army struggles to disarm people in the north despite driving extremists out of major towns in 2013 and a peace deal signed between Tuareg separatists and the government in late June.