Most of the 32 victims of this week's gunbattles in northern Kenya were buried in a mass grave Wednesday as the country's scorching drought exacerbates tensions over land and water.

Drought has driven millions of Kenyans to seek food aid this year, and cattle rustling among rival tribes is a key way of replenishing valuable herds. Tuesday's battles pitted the Samburu against the Pokot tribe.

"This is the worst drought in nine years ... we are really on the cusp of a major, major disaster," said Brenda Barton, a spokeswoman for the U.N.'s World Food Program.

Barton said people have been bringing their cattle hundreds of miles (kilometers) in search of grass or water. "Their cattle are dying, people are pulling their children out of school, malnutrition are rates are raising," she said.

Raphael Letimao, legislator for Samburu East district said the government organized a mass burial for the 21 Samburu killed in Tuesday's raid. The 11 Pokots, meanwhile, were being taken to a mortuary as it is considered taboo to bury rival tribes together.

The dead included women and children, and dozens of people also were wounded, Letimao said.

Fighting between nomadic tribes in the region that encompasses northern Kenya, Uganda, southern Sudan and Ethiopia is common. But the raids have become increasingly lethal as tribal warriors have acquired modern weapons. Arms have flooded the region following conflicts in Uganda, Sudan and Somalia.

This year's drought has shriveled crops, killed cattle and driven millions of Kenyans to seek emergency food aid. The problems have reached Kenya's capital, Nairobi, where the government has started power rationing.

With rivers thinning to a trickle and mountaintop glaciers shrinking, there is not enough water to fully run hydroelectric plants.