Thousands fled their homes in eastern Democratic Republic of Congo on Sunday after "open combat" between rebels loyal to renegade general Laurent Nkunda and government troops, the army said.
"We are in open combat. There is heavy artillery gunfire" the head of the army (FARDC) in the restive Nord-Kivu region, general Vainqueur Mayala, told AFP Sunday.
"At the moment we've got two dead within our own ranks" Mayala said as Nkunda's men claimed to have killed dozens of FARDC troops.
No independent death toll was available Sunday night.
The evening battles began in the hills north of Goma, the regional capital of Nord-Kivu, between the towns of Rugari and Rumangabo -- where the 9th brigade of the FARDC are stationed.
Separately the army has issued an ultimatum to the Mai Mai militia to lay down their arms by Monday.
Confirming the deadline, Mayala said: "If they do not obey this ultimatum we will track them down and find them."
Earlier there were clashes Sunday morning and again late afternoon between Nkunda's forces and the FARDC after the renegade general's forces infiltrated Rugari Saturday night and briefly occupied the road from Goma to Rutshura, said Sylvie van den Wildenberg, spokeswoman for the UN peacekeeping mission in DR Congo (MONUC).
"We immediately sent a rapid reaction force with armoured vehicles and the insurgents retreated to hills further east at our arrival," said MONUC military spokesman Major Prem Kumar Piwari said.In Rugari a FARDC truck could be seen abandoned, riddled with bullet holes, on the side of the road following what Piwari said were clashes between the army and the rebels.
MONUC's van den Wildenberg said fighting had resumed in Rugari on Sunday afternoon adding that the UN mission had despatched a "rapid intervention force."
She warned that the blue berets would not allow the rebels to retake the positions on the key Goma to Rutshuru road.
She added: "We are extremely concerned about the situation and are calling again on the militias to lay down their arms and on the rebels to exploit the extension of the deadline they agreed with the government to give up their arms."
On Saturday the FARC deployed three helicopter gunships to the area and thousands of residents fled the villages of Bunagana and Jomba, northeast of Goma and near the Ugandan border, following battles between Nkunda's forces and local Mai Mai militia.
Civilians interviewed said they had fled fighting not only between supporters of Nkunda and Mai Mai militia but also Rwandan Hutu rebels from the Democratic Forces for the Liberation of Rwanda (FDLR), van den Wildenberg said.
The FDLR, whose members are accused of having taken part in the 1994 genocide of Tutsis and moderate Hutus in neighbouring Rwanda, denied being involved in any fighting with Nkunda's forces.
The eastern province of Nord-Kivu has been the site of rebellions that have plunged DR Congo into wars on two separate occasions, from 1996 to 1997 and from 1998 to 2003.
Since August, it has been the site of clashes between the Congolese army and an estimated 6,000 troops loyal to Nkunda, a Tutsi former general who says he is defending local minorities against the army.
Since the end of last year, violence in Nord-Kivu has prompted more than 370,000 people to flee, and the UN estimates that about 750,000 are displaced in total.
The latest violence comes ahead of a visit to Washington by DR Congo President Joseph Kabila on Friday when he will meet US President George W. Bush.