By Adam Mynott
BBC News, Nairobi
Attempts are continuing in Kenya to solve the crisis which erupted after last week's disputed election. Hundreds of people have been killed in the largely inter-tribal violence which followed.
Kangemi is an ugly slum on the road leading out of Nairobi up towards the escarpment above the Rift Valley and on to Naivasha.
Political tensions have brought ethnic divisions to the surface
Under tin roofs and behind flimsy wooden doors live 100,000 people. They are the poorest of the Kenyan poor.
Few have permanent employment. Crime is rife and Aids, TB and other afflictions take a disproportionate toll on the residents of Kangemi.
Martin Seth, his wife and five children live here in a room 10 feet by 10 feet (3m by 3m). They all sleep in one bed.
They cook, eat, play, read, listen to the radio, chat, are ill, get better, laugh and cry in this cramped place.
I spoke to Martin on 28 December 2007 - the day after the elections. He had a broad grin on his face. He had just received his Christmas bonus. His pregnant wife had just got back from her family home in western Kenya.
"I am a happy man," he said.
This was the first time I had seen a glimmer in the four years that I had known Martin of any ethnic prejudice
I asked: "Who did you vote for? President Kibaki like last time?"
"No," he said, the grin dropping from his jaw.
"I will never vote for him again. He is not one of us."
"What do you mean?" I said.
"You understand - he is not one of my people."
This was the first time, in the four years that I had known Martin, that I had seen a glimmer of any ethnic prejudice.
Ethnicity is deeply ingrained into life in Kenya. It would be ludicrous to suggest otherwise.
Every Kenyan knows his tribe and feels not unnaturally a sense of pride in his origins.
Military police are guarding key points in Nairobi
There are more than 40 tribes in Kenya. Some like the Kikuyu are vast. Others number just a handful.
Hostility between different tribes does well up suddenly. Such violence finds its origins in arguments over land or water or grazing, not xenophobia.
But now Martin was tapping into feelings that had lain dormant.
"I am a Luyah," he told me. "The Luyah and the Luo are together to get the Kikuyu out of government."
Raila Odinga, the opposition leader who claims to have won the election, is a Luo. His number one lieutenant, Musalia Mudavadi, is a Luyah.
On Sunday just minutes it seemed after Mwai Kibaki was confirmed and sworn in as president for another five years those dormant, ethnic sensitivities erupted in a vicious, gruesome display of chauvinism.
It started with word that violence had broken out in pockets in slums in Nairobi.
In Mombasa there were reports that gangs of youths were rampaging through the Western city of Kisumu.
Then my wife got a call from Martin.
Kenya is a country in danger of tearing itself apart. Every day of unrest, violence and hatred may take another month of healing to put right
"Things are bad here," he said "very bad."
Then a click and the line went dead.
We tried calling Martin all night but his phone was either off or there was no reply. We eventually got through to him in the middle of the following day.
He told us houses in Kangemi had been destroyed.
Mobs of youths belonging to tribes that had united under Raila Odinga had rampaged through the slum, picking out Kikuyu properties and setting them on fire.
"I am scared," he said, "of course I am. And in the middle of all this my wife has given birth to our son. We are very worried - worried about what will happen to us. People are being killed".
Similar sickening events were taking place across Kenya.
But it was another 24 hours before the true horrors unleashed by the election crisis became apparent.
The killing of about 30 people, many of them children, burned to death in a church on the outskirts of Eldoret exposed the depravity of the human spirit.
Country in danger
I got a warning perhaps of the events looming in Eldoret when a friend named Lucy called to say that she had tried to drive to the town in the Rift Valley to rescue a colleague trapped by the violence.
She set off with a friend, a Kikuyu, and they drove towards the town. Soon after they took the Eldoret turning off the Naivasha-Kisumu road they encountered their first road block.
Ethnic groups other than the Kikuyu are now seeking shelter
It was manned by four or five youths. Lucy said none of them looked more than 14 or 15 years old.
"Are there any Kikuyus in your car?" the boys asked. "If so we will kill them."
Lucy turned back to Nairobi.
In Kangemi, Martin says there is now a backlash aimed at his tribe and others who did not vote for President Kibaki.
He is now sleeping outside his house for fear of it may be burned at night. Alongside his mattress he has a heavy iron bar. He and his friends sleep in shifts.
"If they come for us," he said "we will be ready for them."
Kenya is a country in danger of tearing itself apart. Every day of unrest, violence and hatred may take another month of healing to put right.
Martin's newborn son, Raila, arrived in the world in the midst of this terror and killing.
From Our Own Correspondent was broadcast on Saturday, 5 January, 2008 at 1130 GMT on BBC Radio 4. Please check the programme schedules for World Service transmission times.