Tens of thousands of people have been evacuated from the city of Goma in the Democratic Republic of Congo over fears of another volcano eruption.
Local authorities have said Mount Nyiragongo could erupt once again with little warning.
The volcano, located 10km (six miles) from Goma, erupted over the weekend, killing 32 people and leaving thousands homeless, according to the UN.
The city was largely spared and some residents had started returning.
But it has since been rattled by aftershocks and two cracks spanning several hundred metres in length have appeared in the ground.
On Thursday Ndima Kongba, the military governor of North Kivu province, said magma had also been detected underneath Goma and nearby Lake Kivu.
Tremors have also been felt as far away as the Rwandan capital, Kigali – which is more than 90km away.
“Right now we can’t rule out an eruption on land or under the lake,” Mr Ndima said.
It is very important to stay away from the lava flows, because of the danger of death from suffocation or burns.
“People should take the bare minimum with them, to make sure everyone has a chance to get on,” he said. “The evacuation must be carried out calmly and without haste.”
“My God keep us safe,” he concluded in his statement.