Political and land rivalries have reinforced each other this year

Ten houses were razed to the ground and some people burnt to death, while others were shot dead, police spokesman Eric Kiraithe told the BBC.

It is unclear if the overnight clashes are linked to election clashes which killed some 1,500 people this year.

The political crisis also reignited long-standing land and economic disputes in parts of Kenya. A deal was signed last week to end the violence.

Armed police have been deployed to the Mount Elgon area in pursuit of the raiders but no arrests have been made.

The dispute between the rival Sabaot and Soi Kalenjin communities has lasted for more than a year.

'Message of Hope'

Land disputes are one of the issues to be tackled as talks between the government and opposition were to resume in the capital, Nairobi.

Parliament is to convene on Thursday to discuss the deal under which opposition leader Raila Odinga is to become prime minister and share power with President Mwai Kibaki.

Former UN Secretary General Kofi Annan, who brokered the peace deal, left Kenya on Sunday after more than a month.

On Monday, the Daily Nation newspaper published a "Message of Hope" from Mr Annan, in which he urged Kenyans to make sure their leaders stuck to the terms of the power-sharing deal they had reached.

"You and your country can move forward and find some solace in healing, if there are processes of justice, truth and reconciliation that will take leadership from your new government, but it will also take commitment from all of you," he wrote.

Former Nigerian Foreign Minister Oluyemi Adeniji is taking over as the chief mediator.