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.