The defence minister of the Democratic Republic of Congo (DRC) has ordered the army to seek out and arrest Bosco Ntaganda, the ex-general who led a group of mutineers now known as 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.
A senior M23 rebel said on Saturday that the group would not advance on other urban areas if talks went ahead.
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.
'Come here and negotiate'
"Our aim is not to go to even Rutshuru, not even Goma," Colonel Vianney Kazarama, M23's political commissar, told the Reuters news agency in Bunagana.
"We want to remain here and call the government to come here and we negotiate."
Kazarama was referring to larger towns in North Kivu province, which has been swept up in violence since last March after the rebels defected with Ntaganda, who is wanted by the International Criminal Court for suspected war crimes.
"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 said.
Kazarama did not set out demands 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.
The Kinshasa government was not available to comment. The timing of the offer of talks a day after capturing territory from the government suggested the rebel troops may have been seeking to strengthen their hand in any negotiations.
The UN Security Council on Friday condemned attacks by the rebels on peacekeepers in the area after an Indian soldier was killed.
DRC soldiers 'flee'
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 groups in the DRC.
Despite outnumbering the rebels 10 to one, the FARDC, DRC's national army, has been unable to dislodge them from hilltop hideouts.
About 600 DRC soldiers were reported to have fled across the frontier into neighbouring Uganda on Friday, while the UNHCR, the UN refugee agency, said it had registered 5,000 refugees crossing the border since Thursday.
In Bunagana, less than a kilometre from the border, military clothing and helmets lay scattered in muddy tracks.
The rebels showed off artillery cannons and anti-aircraft guns that had been abandoned by the fleeing troops.
Inside Uganda, DRC troops rested in the grounds of military barracks. In a nearby clinic, medics treated more than two dozen soldiers, some of whom had suffered gunshot wounds. An officer denied his men had been overpowered.
"In [the] military there are lots of tactics and withdrawal is one of the tactics, so we withdrew," Mumbere Kanzau, a deputy battalion commander, told reporters near the border post.
When asked why the troops had dropped their weapons, he said: "You find yourself across the border in a country with its own laws, you have no option but to lay down your gun and follow the rules of the foreign land."