Iran Press/ Africa: The attackers struck as the convoy, escorted by ICCN rangers, left Kivandya village near Virunga national park which is home to half the global population of endangered mountain gorillas and the scene of frequent militia attacks.
The fourth victim was one of the technical workers travelling in the convoy who were implementing a project to support communities around Virunga, ICCN said in a statement.
A further six people were wounded, it said.
Virunga has been caught in the middle of militia activity that has destabilised surrounding South Kivu province since civil wars fought around the turn of the century.
According to Reuters, the ICCN warned of a resurgence of violence in February after suspected Mai Mai militants attacked a ranger position in Virunga, killing one and injuring two.
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