When Gabriel Okelo rose early Thursday to join a banned opposition rally, he did not take his machete. But he was sure he would be using it to kill again very soon.

Just the day before, he said, he had slashed two people to death because they were from a rival tribe.

It wasn't hard, he recalled. It was night, about 8, and he was among 50 other members of his Luo tribe who rampaged through a suburb nine miles east of Nairobi, the capital, named Uhuru -- "freedom" in Swahili.

"It is the first time I ever killed," said Okelo, who is about 20. "I never imagined it would come to this. It was not a planned thing at all.

"I was angry. When you are angry, it's easy."

Opposition leader Raila Odinga called the rally Thursday to protest what he claims is the rigging of last week's presidential election by incumbent Mwai Kibaki. Police used tear gas and a water cannon against protesters as they gathered, and Odinga postponed the demonstration. But he announced that one would take place today and every day until Kibaki leaves office.

Desmond Tutu, the South African Nobel Peace Prize laureate arrived Thursday, joining diplomats who were pressing for a political deal to end the violence. But many of those caught up in it, perpetrators and victims alike, feel it's too late. Life will not return to what it was.

There always has been an undercurrent of tribal tension in Kenya, but the East African country has avoided the kind of wholesale violence that has plagued nearby countries such as Rwanda. The dispute over the election, however, has left about 300 dead from Kisumu in the west to Mombasa on the Indian Ocean.

For Okelo, any deal with Kibaki is unthinkable now.

And to Jane Kagwiria, 32, sitting Thursday with her four children outside an air force base after she was forced to flee tribal violence in Nairobi's Mathare slum neighborhood, the chances of peace seemed to be ebbing away.

Odinga, like Okelo, is a Luo. Kibaki is a member of the Kikuyu tribe, Kenya's largest, which other ethnic groups accuse of having dominated politics and business here for decades.

But as days pass, more tribes are being caught up in the violence, and Odinga's ability to restrain it looks increasingly questionable.

Okelo said the ban on Thursday's rally would only worsen the violence. He was frustrated and angry: He had walked nine miles from his home to join the protest rally at Uhuru Park in downtown Nairobi, only to find the area blockaded by riot police.

Short and wiry, he spoke in soft tones -- but anger shone in his eyes. As he declared that he had been robbed of his rights, other protesters crowded around him, interjecting the opposition slogan: "No Raila, no peace!"

Some said they wanted guns.

"It's Kenya versus Kikuyus. We are slaughtering them and we will keep slaughtering them. It will go on and on and on in all parts of the country. It will be war. Religious leaders have been preaching peace. Peace, peace! But there's no justice," he said.

Okelo's claim that he had killed two people the night before could not be verified, but it is clear that there are young men all over Kenya committing similar deeds.

In the slums of Nairobi, corpses with ugly machete wounds keep turning up. Each morning, bodies lie like forgotten parcels in the alleys. But daylight brings no relief. In many areas, the Kikuyus are fighting back, evicting and killing Luos.

The emergency ward at Nairobi's Kenyatta National Hospital was in chaos Thursday, with doctors rushing about, assessing victims' chances for survival as they came in. Patients on trolleys crammed the entrance, most with machete cuts, burns or fractures.