Ugandan authorities said on Sunday they were forced to separate Kenyan refugees according to tribe as a result of growing ethnic tensions and two failed poisoning attempts.
More than 6,000 Kenyans fled to Uganda to escape two weeks of riots and ethnic clashes that have killed 500 people in their homeland since President Mwai Kibaki's disputed re-election.
Rivalries between some of the refugees have simmered since their arrival, and the arrest of two men caught trying to poison food for other displaced Kenyans pushed hostilities higher.
"We arrested two men thought to be Kalenjin militias mixing poison in refugees' food at a primary school that is acting as the refugees' reception centre," said Bimpabaza Hashaka, the top government official in Uganda's eastern Tororo District. Kalenjin tribesmen in Kenya have been responsible for many recent attacks on members of Kibaki's Kikuyu ethnic group.
Hashaka told Reuters that Friday's incident in the border town of Malaba followed a similar one earlier last week when another man was found mixing poison into beans being prepared for Kikuyu refugees sheltering at a nearby church.
That man was also arrested, but later escaped from jail. Separately, Hashaka said two wounded Kenyan refugees had been admitted to hospital after they fought over the election result, only to resume their battle in front of doctors.
"They came from warring tribes," the official said.
The UN World Food Programme is due to begin food distribution to displaced Kenyans in the area on Monday.
But due to the rising tensions, Hashaka said, the Ugandan authorities had been forced to segregate the refugees into three ethnic groups of Kikuyus, Luos and Kalenjins. "We are reminding them that the law will catch up with anyone who attacks another," he said.