Eruption of Mount Nyiragongo killed at least 15, sent 30,000 people fleeing Goma and destroyed more than 500 homes.
Tens of thousands of people have fled the Congolese city of Goma after officials ordered the evacuation of parts of the city due to the risk of further eruptions from Mount Nyiragongo.
The evacuation order came after powerful aftershocks rocked the country on Tuesday morning, with tremors shaking the region every 10 to 15 minutes.
“Current data on seismicity and the deformation of the ground indicate the presence of magma under the urban area of Goma, with an extension under Lake Kivu,” Ndima Kongba, military governor of North Kivu province, said on Thursday in a broadcast public address.
“Right now we can’t rule out an eruption on land or under the lake, which could happen very soon and without warning.
“The situation can change rapidly, and is being constantly monitored,” he said, adding that the evacuation is necessary and should be done calmly.
But on Thursday morning, thousands of people evacuated by car, by motorbike and on foot, with bundles of possessions on their heads, creating traffic jams across the city. Many others left on large boats across the lake that abuts the city of nearly 1.5 million.
Videos shared on social media showed dozens trying to board boats at the port.
“People should take the bare minimum with them, to make sure everyone has a chance to get on,” Ndima said, adding that authorities had arranged transport towards Sake, approximately 20km (12 miles) west of Goma.
On Wednesday, the UN said it was temporarily relocating about 250 non-essential staff, roughly half of its aid workers, and about 1,500 of their dependents to the city of Bukavu, some 50km (30 miles) south.
Saturday’s eruption sent rivers of lava streaming down the hillside from Mount Nyiragongo, destroying hundreds of homes and forcing thousands to flee, but stopped 300 metres (984 feet) short of Goma airport, the main hub for aid operations in the east of the Democratic Republic of thr Congo.
Goma lies a dozen kilometres (eight miles) from the volcano.
The ash cloud caused by the eruption has closed down airports in Goma and Bukavu, and is likely to cause respiratory diseases, the UN Office for Coordination of Humanitarian Affairs (OCHA) said in a statement on Wednesday.
More than 200 small and medium earthquakes have since caused cracks in buildings and streets in Goma. The cracks, almost 60cm (2 feet) wide in some places, have caused panic among residents unsure if the danger has passed.
A so-called strato-volcano nearly 3,500 metres (11,500 feet) high, Nyiragongo straddles the East African Rift tectonic divide.
Its last major eruption, in 2002, killed some 100 people.