KINSHASA, Congo — Rebels from neighboring Uganda kidnapped 90 children in eastern Congo, and weeks of fighting in the restive border region have forced 100,000 people to flee their homes, U.N. officials said Monday.

The children were taken away from two village schools last week during a series of attacks in Orientale province, the United Nations Children's Fund said. Local officials identified the attackers as members of Uganda's Lord's Resistance Army rebels, it said.

"UNICEF is very concerned that (the children) will now be forced to fight or support fighting, putting their lives at risk," regional administrator Julien Harneis said in a statement calling for their release. The rebel group has bases in the nearby forest.

Three civilians were killed in the attacks, and a village chief and two Italian also missionaries were abducted, UNICEF said. The attackers burned the village of Kiliwa, leaving only the health center standing, it said.

Clashes continued to erupt between Congolese rebels and army troops farther south, in the province of North Kivu.

Insurgents and soldiers fought Monday in the towns of Sake and Kiroshe, southwest of the provincial capital of Goma, said a spokesman for U.N. peacekeepers, Lt. Col. Jean-Paul Dietrich. He said several civilians were reported wounded, but he had no other details.

After years of fighting between warring militias, eastern Congo had appeared on the road to calm following a peace deal signed last January by the national government and a host of rebel groups. However, the area fighting broke out again in late August.

At least 100,000 people have been forced from their homes in less than four weeks, said Christophe Illemassene, a spokesman with the United Nations' humanitarian agency. He said fighting had kept aid workers from reaching many of those who fled.

The insurgents are loyal to eastern warlord Laurent Nkunda, who led rebels backed by neighboring Rwanda during Congo's 1998-2002 war. Nkunda launched a new rebellion, claiming Congo's transition to democracy excluded Congo's minority Tutsis.

Congo held its first democratic elections in more than four decades in 2006, but the new government has struggled to assert its control in the vast country, particularly in the east.