Witnesses in the eastern Democratic Republic of Congo report heavy fighting between army troops and renegade soldiers loyal to General Laurent Nkunda.

Army Colonel Delphine Kahimbi says a large force of Nkunda's soldiers launched a pre-dawn attack Thursday on an army post in Katale, North Kivu province.  Kahimbi told the French News Agency that about 30 troops have been wounded.

Other witnesses say the sides exchanged machine gun and heavy weapons fire for at least five hours before the fighting subsided with the army still controlling the base.

The army has been fighting Nkunda's forces for several years as part of efforts to gain control over expansive and volatile eastern Congo.  That fighting flared up in North Kivu earlier this week, leading to an appeal for calm by the U.N. peacekeeping mission in Congo.

The U.N. mission is there to help Congo transition from a five-year civil war that ended in 2003.

However, the government in Kinshasa has not been able to assert full authority in the country's east, which is home to many militia groups and rebels from Rwanda.

The conflicts are complicated by ethnic tensions between Hutus and Tutsis.  The fighting Thursday involved the so-called Charlie Brigade, a mix of soldiers from both ethnic groups.

U.N. officials say opposing factions in the brigade fought a battle in North Kivu earlier this week.

Some information for this report was provided by AFP, AP and Reuters.