SAKE: Families fleeing a volcano eruption in eastern Democratic Republic of Congo said on Friday they were struggling to find enough food and water as the United Nations called for aid and warned about the risk of cholera.

At least 31 people died when Mount Nyiragongo sent a wall of lava spreading towards Goma on Saturday last week, destroying 3,000 homes along the way and cutting a major road used to bring aid to the strife-torn region.

The lava stopped just short of the city limits, but thousands more people fled early on Thursday when the government warned that the volcano, one of the world's most active, could erupt again.

Many escaped to Sake, a town 13 miles (20 km) northwest of Goma that is prone to cholera outbreaks, UNICEF said.

People slept wherever they could - on the side of the road and inside classrooms and a church. Kabuo Asifiwe Muliwavyo, 36, told Reuters she and her seven children had not eaten since arriving on Thursday.

"They told us that there will be a second eruption and that there will be a big gas explosion," she said as she cradled her crying one-year-old. "But since we moved, there is nothing here ... We are starving."

Around 400,000 people need support or protection, the U.N. children's fund (UNICEF) said in a statement.

"With an increased risk of a cholera outbreak, we are appealing for urgent international assistance to avert what could be a catastrophe for children," UNICEF's representative in Congo, Edouard Beigbeder, said.

UNDER THE STARS

Danga Tungulo and his four children slept next to the road in Sake. Some local residents brought them water, but they had not eaten since they left Goma the previous day, he said.

"They told everyone that assistance would be organised, that money would be disbursed by the government," said Hassan Kanga, a lawyer who fled after the eruption. "And yet, you find us under the stars."

The evacuation order was issued around 1 a.m. local time on Thursday after radar images showed molten rock flowing under Goma.

The movement of magma caused cracks in the ground and hundreds of earthquakes, which could allow it to burst through to the surface in a fresh eruption, the Goma Volcano Observatory (OVG) said.

The frequency and intensity of the ground tremors had lessened in the last 24 hours, suggesting the risk of a fresh eruption was subsiding, Celestin Kasareka Mahinda of the OVG said on Friday.

"I don't think we will have a second eruption. The problem is the risk of fractures, but the risk is small, around 20%," he told Reuters.

Some people who had fled to Sake crowded into trucks later on Friday to return to Goma. Dozens of people who had fled in the opposite direction to neighbouring Rwanda also crossed back into Congo, photos shared by the Rwandan government showed.

Congolese authorities, meanwhile, reopened the main road which was split in two by lava, the U.N. Office for Coordination of Humanitarian Affairs (OCHA) said on Thursday.

Goma is major humanitarian hub supplying aid to a region hit by decades of unrest.