The situation is serious but "under control" following the eruption of a volcano in the Democratic Republic of Congo, President Felix Tshisekedi said on Saturday.
"The situation is certainly serious but it is under control," he told a news conference, after his government mistakenly announced that a second volcano had erupted, a week after causing devastation and sparking a mass exodus.
"There is an underground lava flow that can arise anytime anywhere in the city," Mr Tshisekedi warned, strongly advising against people returning to the eastern city of Goma.
"The lava is no longer in the crater, but the volcano remains active, so we have to be wary and that's why we don't want to rush things by bringing back the populations," he said.
It comes as the government is increasingly criticised over a looming humanitarian crisis, with around 400,000 residents having evacuated Goma after a week of rolling aftershocks.
Africa's most active volcano roared back to life a week ago, sending terrified people in Goma running for their lives as rivers of lava destroyed homes and claimed nearly three dozen lives
Congolese are evacuated across cooled lava from the town of Goma in the aftermath of Mount Nyiragongo volcano over Goma. Source: AAP
"The displaced people left following an unprecedented situation: the eruption itself was not foreseen by any observatory in the world... no one saw it coming, it happens", the president said.
He added that he preferred "to take care of displaced populations, rather that they are decimated by a natural disaster".
More than 1,000 refugees left a camp in Rwanda to return to DR Congo on Saturday.
Mr Tshisekedi held a cabinet meeting Friday in which he called on the government to "redouble its efforts to better deal with the humanitarian situation".
Criticism has been growing over the government response after an evacuation order on Thursday was met with fear and traffic jams, many not knowing where to go.
"The population had the impression of being abandoned to their sad fate," said the newspaper EcoNews, calling it "a perfect illustration of the fact that the state does not exist".
"The state has decided to evacuate the population of Goma and Nyiragongo without giving any help," citizen movement Lucha tweeted.
A Congolese porter helps people evacuate across cooled lava from Goma in the aftermath of Mount Nyiragongo's eruption. Source: AAP
Prime Minister Jean-Michel Sama Lukonde defended the government's response, saying the event had "no similarity to previous eruptions in that it occurred without warning signs".
The mounting humanitarian crisis comes in a region that has been ravaged by violence for three decades. Access to drinkable water is particularly urgent, according to aid organisations in the area.
"Sometimes it's the war, now it's the volcano," a customs officers grumbled Saturday.
