Rebels from the Democratic Republic of Congo (DRC) have taken control of three towns in the country's eastern North Kivu province, a spokesperson for the group has said.
The rebels, known as the M23 movement, had taken Rutshuru and the towns of Ntamugenga and Rubare, less than 10km away, on the road to the provincial capital Goma, by midday (local time) on Sunday.
The rebels said they did not face any opposition from the FARDC, the DRC's national army.
"Our men have just taken the town of Rutshuru. On Saturday evening the FARDC came down to our position at Mbuzi," M23 spokesman Lieutenant Colonel Vianney Kazarama told the AFP news agency.
"We decided to pursue them and they lost Ntamugenag, then we came down Rubare."
Sporadic gunfire was later heard in Rutshuru, but may have been celebratory shots fired into the air. The rebels' seizure of Rutshuru has promulgated fears of escalating violence in the country's eastern region.
Eight peacekeepers from the UN's mission in DR Congo (MONUSCO) fled Rutshuru for a UN base five kilometres away in Kiwanja, close to which numerous local inhabitants have set up refugee camps.
'Come here and negotiate'
The move in to Rutshuru comes a day after the M23 movement told the Reuters news agency that they had no intention of taking Rutshuru or the provincial capital Goma.
"The defence and security services are ordered to urgently relaunch an operation to find and arrest [Ntaganda and five other officers]".
- Alexander Tambo, Defence Minister
"Our aim is not to go to even Rutshuru, not even Goma... We want to remain here and call the government to come here and we negotiate," Colonel Vianney Kazarama, M23's political commissar, said.
"When we defected from the national army, we told the government, 'Let's keep negotiating and we keep the peace that is existing'.
"But the government instead said it is very powerful... they said they will defeat us."
Kazarama did not set out the group's demands on Saturday but said their faction's integration into the national army had failed because they were treated unfairly.
He also said the government had failed to repatriate refugees living in Uganda and Rwanda.
On Saturday, the DRC government ordered the army to seek out and arrest Bosco Ntaganda, the ex-general turned leader of the M23 movement.
The M23 called for negotiations with the government on Saturday to end violence in the east of the country, a day after seizing a minerals transit town near the border with Uganda.
The M23 seized the border town of Bunagana on Friday in fighting that has forced thousands to flee their homes.
A statement, signed by defence minister Alexander Tambo, said Ntaganda and 13 of his deputies had been dismissed from the army and went on to say that "the defence and security services are ordered to urgently relaunch an operation to find and arrest [Ntaganda and five other officers]".
The new fighting in mineral-rich North Kivu province has dampened hopes of a revival for the region after a short lull in two decades of instability.
It risks dragging the vast, loosely governed central African state back into war and damaging fragile relations with Rwanda, which has repeatedly denied allegations that the rebels are receiving cross-border support.
The UN Security Council on Friday condemned attacks by the rebels on peacekeepers in the area after an Indian soldier was killed in Bunagana, a town near the Ugandan border, about 20km south of Rutshuru.
Bunagana fell into rebel hands after the clash, according to the M23 spokesman and local civilians, causing around 600 Congolese soldiers to flee into Uganda.
Despite outnumbering the rebels 10 to one, the FARDC has been unable to dislodge them from hilltop hideouts.
Rwanda has denied allegations in a report by UN experts that provided the strongest evidence yet that officials of President Paul Kagame's government were providing military and logistical support to armed rebel groups in the DRC.
Two months of fighting in the resource-rich region has pitted government troops against former Congolese Tutsi rebels, who were integrated into the army but defected this year and formed the M23 rebel movement.