The gang was baying for blood and wouldn't believe Peter Oduri as he tried to deny being a member of the Luo tribe. But the 10 youths armed with pangas knew how to check, writes Rob Crillyin Naivasha.
They pushed their way into the tiny shack and forced him to strip naked, whooping with delight when they saw the evidence. Oduri had not been circumcised, marking him out as a Luo living far from home in the small market town of Naivasha.
"They cut him down with a panga to his neck," said his brother John, speaking in the safety of the town's police station.
The attackers were from the Kikuyu tribe, which has launched a string of revenge attacks in the past week as Kenya descends into a new round of ethnic violence.
Some 800 people have died since President Mwai Kibaki was sworn in at the end of last month after a ballot dismissed as flawed by most observers. Raila Odinga, the main opposition leader, insists the election was stolen from him.
The violence has transformed a country once seen as a haven of stability and economic growth into a cauldron of ethnic tension.
At first opposition supporters, drawn largely from the Kalenjin and Luo tribes, had targeted Kikuyus from the same ethnic group as Mr Kibaki.
The lakeside town of Naivasha, about 55 miles from Nairobi, had escaped the weeks of clashes until Sunday morning. The Kikuyu gangs arrived at about 8.30am and began hacking and torching their way around the town in a day of revenge.
Mr Oduri, his tatty clothes still spattered with blood, said the attackers were from out of town. They were guided by locals from house to house, seeking out opposition supporters.
"They were hunting Luos," he said.
At least 22 people were killed in the town during the weekend. Most died after they were chased into shacks that were then set alight, said Grace Kakai, a police commander.
Yesterday, Naivasha remained tense. Smoke still rose into the sky from Kabati slum, the scene of the worst trouble on Sunday. Volleys of gunfire echoed around the town as police fought running battles with youths.
At one point rival tribes confronted each other close to the flower farms that make this area one of Kenya's richest. Police fired tear-gas and live rounds to keep them apart. The attacks in Naivasha provoked a series of tit-for-tat exchanges elsewhere.
Hundreds of Luo demonstrators took to the streets of Kisumu, an opposition stronghold in western Kenya. They set light to barricades and began looting shops. Eldoret in the Rift Valley saw similar scenes.
The latest violence shows the huge task facing Kofi Annan, former secretary general of the United Nations, as he attempts to mediate between Mr Odinga and Mr Kibaki.