Three members of the United Nation's peacekeeping mission in the Democratic Republic of Congo were kidnapped Thursday in the eastern North Kivu province, a U.N. source said.

"Three members of MONUSCO (the 20,000-strong U.N. peacekeeping force)... have been kidnapped in Kibumba", some 30 kilometers (20 miles) north of the provincial capital Goma, the source told AFP.

Six U.N. peacekeepers from Ukraine were arrested in the Democratic Republic of Congo Wednesday for illegally being in possession of Congolese military uniforms.

The six were detained at Goma airport in the country's restive east along with the supplier of the uniforms, a Congolese man, according to Lieutenant Colonel Olivier Hamuli, a spokesman for the Congolese army (FARDC).

The first in a fleet of United Nations drones will begin monitoring rebel activity on the borders of the Democratic Republic of Congo next month, a U.N. commander said Wednesday.

General Carlos Alberto Dos Santos Cruz, commander with the U.N. peacekeeping brigade in the country, said the unarmed drone would be airborne by the last week of November.

South Africa has warned rebels fighting in the Democratic Republic of Congo not to try and retake the battleground city of Goma Friday after a week of escalating violence.

South Africa is part of the U.N. peace enforcement military task force to the country's troubled eastern region bordering on Rwanda.

Fresh fighting flared in the resource-rich eastern Democratic Republic of Congo Thursday, with government forces backed by U.N. troops shelling rebels near Goma and tensions spilling over into neighboring Rwanda.

Artillery fire could be heard around Kibati north of Goma, the capital of the turbulent North Kivu province, where the DR Congo army and a newly-formed U.N. intervention brigade have been battling M23 rebels for a week.

The Democratic Republic of Congo's M23 rebel group warned Saturday that it would not rule out recapturing the main eastern city of Goma if Kinshasa reneged on its pledge to start direct talks.

The M23 seized Goma in November last year and only pulled out under intense international pressure and after Kinshasa promised to discuss the group's grievances.

U.N. chief Ban Ki-moon pledged Thursday that U.N. troops will be in place within "one or two months" to battle armed rebels in the Democratic Republic of Congo's volatile east, as he arrived in the flashpoint city of Goma for a brief visit.

Ban's visit came after three days of sometimes deadly fighting between rebels and government forces that ended months of calm in the mineral-rich east of the country, an area gripped by conflict for more than two decades.

Rebels from the M23 movement and the army fought Monday just north of Goma, a regional capital in the eastern Democratic Republic of Congo that the rebels had occupied briefly in November, both sides said.

An M23 spokesman, Amani Kabasha, said the clashes were taking place 12 kilometers (7.4 miles) north of Goma. Colonel Olivier Hamuli, spokesman for the DRC's armed forces, confirmed the fighting was taking place, without saying if there were casualties.

Six people died when a plane crashed into a residential area of Goma in eastern Democratic Republic of Congo, Transport Minister Justin Kalumba said on Tuesday.

"The toll is six dead," Kalumba said, adding that three passengers had survived.

The pullout of rebel forces from Goma, capital of the Democratic Republic of Congo's mineral-rich east, is "a step in the right direction," DR Congo government spokesman Lambert Mende said Sunday.

"We have indeed seen this withdrawal. We say that it's a step in the right direction," Mende told Agence France Presse after the M23 rebels withdrew Saturday from Goma, which they had occupied for 12 days.