GOMA, Congo - Renegade Congolese General Laurent Nkunda said on Friday the Congolese army had attacked his position, breaking a fragile ceasefire negotiated by United Nations mediators in eastern Democratic Republic of Congo.

"I have told MONUC (the U.N. mission in Congo) that we were attacked this morning in Rutshuru. They say they are in contact with the Congolese army to ask them to stop," Nkunda told Reuters by telephone.

"I think it can be stopped," he said.

U.N. mediators announced the ceasefire on Thursday after nearly two weeks of fighting in volatile North Kivu province in which rebels loyal to Nkunda have battled U.N.-backed government troops, forcing thousands of refugees to flee.

The deal was announced as thousands of Tutsi fighters loyal to Nkunda appeared to have turned the tide on government forces, and were pressing ahead towards the provincial capital Goma.

The worsening fighting in eastern Congo has been a setback to efforts by President Joseph Kabila, who won landmark elections late last year, to achieve lasting peace across the former Belgian colony, scarred by a 1998-2003 war.