Authorities ordered a partial evacuation of Goma, a large city in eastern Congo, early Thursday out of concerns about a further eruption of a nearby volcano.
Lt.-Gen. Kongba Constant, military governor of the North Kivu region announced on the official TV broadcaster RTNC that 10 districts would be evacuated.
Authorities would organise transport, he said, and residents should take along only the bare necessities.
Residents had fled their homes in panic, some even to neighbouring Rwanda, after the Nyiragongo volcano erupted over the weekend.
Some of the lava had flowed toward Goma, but stopped 300m from the airport.
Forty people were still missing, according to UN figures, while some 20,000 people have been left homeless.
Humanitarian relief efforts have been hampered by airport closures in Goma and the neighbouring city of Bukavu.
Three villages and a Goma suburb were destroyed by lava from the volcano in Virunga National Park, about 20km north of the city, near the Rwanda border.
Nyiragongo last erupted in 2002, with lava destroying large parts of Goma at the time, leaving 250 people dead and displacing 120,000.