Police battled protesters in blazing slums on Monday as President Mwai Kibaki began a second term after a disputed vote that has convulsed Kenya, hurt its democratic credentials, and brought a rising death-toll.

As details emerged of a night of violence, witnesses and local media said another seven people had died in Kisumu in west Kenya, a heartland of opposition support. That would bring the death-toll across Kenya since Thursday's vote to about 20.

Trying to defuse one of the most volatile moments in Kenya since 1963 independence from Britain, the government kept a ban on live TV broadcasts, imposed a curfew in Kisumu and other hot-spots, and flooded the streets with security forces.

Siren-blaring ambulances and armoured cars with water-cannons rushed through the streets of Nairobi in the direction of Kibera, Mathare and Kawangware slums.

Kibaki, 76, showed a steely core by swearing himself in within an hour of being pronounced victor in an election denounced as fraudulent by opposition challenger Raila Odinga and questioned by international and Kenyan observers.

Odinga's supporters said he would be declared president at a rival ceremony on Monday, but police banned the event.

"This is the saddest day in the history of democracy in this country. It is a coup d'etat," said Koki Muli, head of respected local watchdog, the Institute of Education in Democracy.

Kibaki supporters celebrated in his highland homeland, and the president urged Kenyans to "set aside the passions that were excited". But hundreds of Odinga supporters ignored the plea.

Shouting "No Raila, no peace!", youths in Nairobi's Kibera slum -- one of Africa's largest -- lit bonfires and set fire to a petrol station on Monday before police in riot gear moved in.

One man was beaten to death by a mob, a witness said.

"We are being oppressed. There's no democracy in Kenya," said Mark Odera, as his eyes watered from a shot of tear gas. "Better to die than live in humiliation."    

Scores of paramilitary police armed with guns, riot shields and batons patrolled the streets and guarded shopping centres to head off potential looters.

Kibaki now faces the momentous task of reuniting a country split along ethnic lines by an election that has brought several dozen deaths, taking into account campaign violence too.

The turmoil threatens to deter investors from east Africa's largest economy and damage Kenya's reputation as an oasis of relative stability in a volatile and war-scarred region.

With a reputation as an amiable, measured and non-confrontational leader, Kibaki turned round a dire economy under his strongman predecessor Daniel arap Moi into average five percent growth since 2002.

A ban on live media broadcasts, within minutes of Kibaki's inauguration on Sunday, was criticised by activists as an attack on press freedom in a country usually described as one of the continent's most vibrant democracies.

While Britain and the European Union expressed concerns, Washington sent its congratulations to Kibaki, a key ally in its war against al Qaeda in east Africa.

So controversial was the final result that the electoral board's chairman had to abandon his public announcement when heckling opposition supporters stormed the podium.

Within the hour, he was joking at Kibaki's side during a swearing-in on the lawn of Nairobi's State House.

From there, smoke could be seen rising from the Mathare, Kibera and Kawangware slums, where pro-opposition ethnic Luos and Luhyas protested at what they see as a stolen victory.

Having led every opinion poll bar one since September, then taken a strong lead in early results, the opposition Orange Democratic Movement (ODM) was dismayed to see Kibaki pip it.

Kibaki took 4.58 million votes to Odinga's 4.35 million -- but the results were marred by accusations<