At least 12 people have been killed in land clashes in west Kenya, police say.
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, 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.
Rabson Mbuya said his wife, three children and housekeeper were among those killed after the attackers knocked on the door of his house in Embaskasi village at the foot of Mount Elgon.
"There was no response," he said, weeping, according to the AP news agency.
"One spilled petrol on the roof before torching it. I heard my wife and children scream but there was no way I could go near and rescue them."
He said he also saw a three-year-old boy hacked to death as he ran from his parents' house.
'Message of Hope'
Armed police have been deployed to the area in pursuit of the raiders but no arrests have been made.
The dispute between the Soy and Ndorobo clans of the Sabaot ethnic group has lasted for more than a year.
The local police commissioner told the BBC that the victims were accused of not paying protection money to the Sabaot Land Defence Force (SLDF) militia.
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.