U.N. High Commissioner for Human Rights Navi Pillay has called for an impartial inquiry into attacks by the Ugandan army on villages in the north.

In a statement issued through her Geneva office on Monday, she said the military operations -- two in January and one in April -- in the Karamoja region had caused heavy loss of civilian life, including women, children and old people.

Her statement, issued after a four-day visit to the East African country, welcomed the Ugandan government's creation of a commission of inquiry to look into the April incident, in which she said up to 25 people may have been killed.

"However, it would be preferable for a commission to be independent of the UPDF (the army) to ensure a fair, transparent and impartial process," declared Pillay, a former senior South African and International Criminal Court (ICC) judge.

"All officers in positions of command during the execution of these three incidents should be investigated, pending possible charges, and clearly, in the circumstances, they should be removed from Karamoja," she said.

She said a helicopter gunship and ground forces had taken part in two attacks, on Jan. 4-7 and Jan. 22, in which at least 19 people were killed, according to official figures.

In the third attack, on April 24, 10 deaths were confirmed. But Pillay said in all three incidents the real death toll was likely to be much higher.

Pillay acknowledged there was a problem in Karamoja, on the borders with Sudan and Kenya, where cattle-rustlers are active.

But she said local communities had been antagonised by heavy-handed efforts to force them to switch from cattle-raising to farming in a barren region not suited to agriculture

"Even more damaging has been the general approach to disarmament, which has involved soldiers rounding up, and sometimes mistreating, large groups of people indiscriminately," she added.

Last Thursday, Ugandan opposition leader Olara Otunnu, a former U.N. undersecretary-general, called on the ICC to investigate President Yoweri Museveni.

He accused Museveni of responsibility for the killing of more than 30 people in a Kampala riot in September, for alleged genocide in northern Uganda, and for alleged war crimes in the Democratic Republic of Congo. The government has declined to comment.

Museveni, who is up for re-election next year, has been hosting a review meeting in Kampala of the ICC, the world's first permanent war crimes court, which Pillay attended.

Reuters