KINSHASA - A senior officer of Uganda's Lord's Resistance Army (LRA) rebel group has surrendered to U.N. peacekeepers in northern Democratic Republic of Congo, a U.N. spokesman in Kinshasa said on Tuesday.

Opiyo Makasi, who was the LRA's operations and logistics commander, had been transferred to Kinshasa and handed over to the Congolese authorities, Kemal Saiki, spokesman for the U.N. mission in Congo (MONUC), told Reuters.

The LRA, whose brutal 20-year war in northern Uganda killed tens of thousands and made 2 million people refugees, signed a ceasefire with Uganda last year but have refused to quit their jungle hideouts in eastern Democratic Republic of Congo.

Saiki said Makasi had given himself up along with his wife.

"He surrendered to MONUC and we arranged for him to be transferred and handed over to the Congolese authorities," he said.

Anneke Van Woudenberg, a researcher in Congo for Human Rights Watch, said that Makasi was not one of the four top LRA commanders indicted by the International Criminal Court in the Hague for crimes such as killing civilians, slicing body parts off victims and kidnapping children.