The situation is "under control" following the eruption of a volcano in the Democratic Republic of Congo, President Felix Tshisekedi said on Saturday after his government mistakenly announced another volcano had erupted.
A week after Mount Nyiragongo roared back into life, causing devastation and sparking a mass exodus, "the situation is certainly serious but it is under control," Tshisekedi told a news conference.
More than a thousand refugees left a camp in Rwanda to return to the Democratic of Congo on Saturday, officials said, after escaping over the border fearing Mount Nyiragongo could erupt again.
Africa's most active volcano roared back to life a week ago, sending terrified people in the nearby city of Goma running for their lives as rivers of lava destroyed homes and claimed nearly three dozen lives.
The eruption stopped, but warnings in recent days that it could blow again sent nearly 400,000 people rushing from Goma, with thousands crossing into Rwanda at a nearby border point.
Around 3,000 people sought refuge at a temporary camp in Rugerero, about ten kilometres (six miles) from the border.
But on Saturday an estimated 1,200 had left for Goma, a Rwanda government official at Rugerero told AFP on condition of anonymity. Military trucks were seen transporting refugees to the border.
William Byukusenge, a construction worker, said he felt the danger had passed.
"My house is in good shape, I have a wife and two kids. If it erupts again, we will come back to Rwanda," the 21-year-old Congolese evacuee told AFP.
But another evacuee, Marie Claire Uwineza, said she had nowhere left to go.
"My house was burned, and I have nothing left," said the 39-year-old, who fled with two of her children.
She was being sent to another camp at Busasamana, around 35 kilometres from the border, along with other evacuees unwilling or unable to return home yet.
At the camp, aid workers hastily erected tents and toilet facilities to meet growing demand.
Boubacar Bamba, the UN refugee agency's deputy representative for operations in Rwanda, told AFP the camp's population had swollen in recent days from around 800 evacuees to closer to 2000.
"There is no time to plan. We plan and execute at the same time, because we are caught short by events," he said.
"This site is designed for a maximum of 3,000 people. The likelihood of receiving more people depends on the activity of the volcano, we do not control that. We are preparing for all eventualities, even if our resources are not sufficient," he added.
DR Congo's government said Saturday that the eruption of a second, nearby volcano it had announced hours earlier was a "false alarm".
Nearly 3,500 metres (11,500 feet) high, Nyiragongo straddles the East African Rift tectonic divide.
Its last major eruption, in 2002, claimed around 100 lives and the deadliest eruption on record killed more than 600 people in 1977.
Volcanologists say the worst-case scenario is an eruption under nearby Lake Kivu -- a so-called "limnic eruption" when lava combines with a deep lake and spews out lethal, suffocating gas across a potentially large area.