After the eruption of the Nyiragongo volcano in Congo, the situation in the lava-threatened border town of Goma remains tense.
The residents of the city of two million people waited anxiously on Monday for any further tremors in the region that could trigger new lava flows.
School lessons would be suspended indefinitely, ordered the responsible gourverneur Ndima Constant after a crisis meeting on Monday night.
Four tourists who were stuck on the mountain peak of Nyiragongo were accompanied down into the valley by a team from the National Institute for Nature Conservation on Monday morning.
According to information from Virunga Park Director Emmanuel Demerode, they were first driven to Rumangabo and from there flown to Goma.
At first nothing was known about their nationality.
The park is Africa's most biodiverse reserve and home to the endangered mountain gorillas.
They are currently being admired in their natural environment by numerous tourists from all over the world.
The day before, residents who had left their homes on Saturday evening in a panic and some of them had fled across the border into neighboring Rwanda reluctantly returned.
Due to the disaster, the Rwandan authorities opened the border and let people pass.
Part of the lava flow had rolled towards Goma, but had stopped in front of the city.
Among other things, the international airport there was in danger of being overrun by the lava.
In Goma, riots broke out in the central prison on Sunday night, as prisoners evidently feared for their lives after the volcanic eruption.
Several shots could be heard from the building complex, as a dpa reporter reported.
The volcano is located in the Virunga National Park, about 20 kilometers north of the city - and therefore also close to the border with Rwanda.
The lava flows mainly flowed through parts of the national park, explained the head of the volcanological observatory of Goma, Celestin Mahinda.
Mount Nyiragongo last erupted in 2002. Back then, lava destroyed large parts of Goma. Around 250 people were killed in the outbreak and 120,000 were left homeless.