Lying on a blood-stained stretcher, Caleb's face is convulsed in pain. "The Kikuyus circumcised me by force," he says, moments before losing consciousness in the hospital's sweltering heat.
The 24-year-old Kenyan is from the Luo tribe, which unlike the rival Kikuyu tribe, does not practice male circumcision.
But in the violent context of Kenya's post-election strife, what has become known as "forced circumcisions" are often outright penile amputations performed with rusty machetes by angry mobs.
In recent days, the usually peaceful town of Naivasha, less than 100 kilometres (60 miles) northwest of Nairobi, has seen some of the worst violence between rival tribal gangs.
The killings were ignited by last month's disputed presidential poll, which saw opposition leader Raila Odinga -- a Luo -- claim that Mwai Kibaki -- a Kikuyu -- had rigged his way to re-election.
"When you cut the genital parts, you bleed a lot and there are a lot of chances that you may die. You suffer like hell," said one medical aid worker at Naivasha hospital.
Such cases of genital mutilations have reported in several parts of the country, notably in several Nairobi slums, since the election dispute touched off a cycle of tit-for-tat killings between rival tribes.
Before passing out from pain, Caleb finds the strength to recount his ordeal.
On Sunday night, "a group of eight men with pangas (machetes) entered. They asked for my ID," he says, explaining that his attackers wanted to see his name and determine which tribe he belonged to.
Voting in the December presidential poll was conducted largely along tribal lines, with the dominant Kikuyus supporting the incumbent while Luos and allied tribes rallied behind Odinga.
"They slashed me and they circumcised me by force. I screamed a lot and cried for help: 'Mum, I don't want to die far away from home'," he says.
Caleb complains that the police arrived on the scene but eventually left him in a poll of blood and made away with the machetes and other weapons left behind by the Kikuyu gang.
His forced circumcision was not the only mutilation he suffered at the hands of his attackers.
Machete wounds to his head are starting to dry up and a blood-soaked compress drips down his ankle, as he awaits treatment from Naivasha hospital's overwhelmed staff.
"The Kikuyus don't want us here. They say we are taking their jobs. When I am well, I will go back home. There is no point of risking my life here," Caleb says.
The young man, who moved to Naivasha alone in November to work in one of the area's many flower farms, is from Kisumu, the country's third city and an opposition stronghold where Luos are the majority.
What started as nationwide protests against Kibaki's re-election rapidly degenerated into ethnically-driven revenge killings, with dominant tribes in each region expelling minorities.
The violence spread to Naivasha last week, with Kikuyus organising themselves in gangs to drive out mainly Luos whom they say have settled their homeland.
"We want to remove the Luos from here because they removed us from Kisumu and Eldoret," says one Kikuyu who refused to reveal his name.
Kisumu and Eldoret are two of the main cities in western Kenya, which saw the worst of the violence that erupterd in the immediate aftermath of the elections.
The young Kikuyu and a mob of armed fellow tribesmen shout "Go home" in unison, standing defiantly outside a police station where some 200 terrified Luos have found temporary shelter and await a bus that will spirit them out of Naivasha.
Close to 1,000 people have died in protests, riots, police raids and tribal clashes across the country since the election.