At least 56 people have been arrested on suspicion of killing 32 villagers, including women and children, in the Tana Delta region in Kenya's southeast coast, police say.
"We launched a major overnight man-hunt for the attackers and arrested 56 suspects who we believe were involved in the attacks," Robert Kitur, chief of the Coast region deputy police, said on Sunday.
Police sent an additional team of 200 paramilitary officers to the region to disarm the fighters, and said among the dead were six women and 13 children.
The violent clashes on Friday saw semi-nomadic Orma pastoralists being attacked by Raiders, settled farmers from the Pokomo ethnic group, with guns, machetes and spears.
Up to eleven Pokomo had also died which authorities described as a reprisal raid following a series of clashes in August in which more than 100 people have died.
The east-African state is due to go to election in March 2013. The on-going dispute between the two groups has been triggered by contested access to grazing, farmland and water.
Hamisi Abdul, a survivor currently recuperating in hospital, said of the attack by the Pokomo: "They hacked everyone they came across with machetes and spears and shot indiscriminately at us, even as we scampered to seek safety in the bushes. It was confusion. We didn't know which direction they were coming from."
Human rights campaigners have alleged that the latest wave of violent attacks have been led by politicians seeking to drive away parts of the local population they believe will vote for rivals in national elections due in March.
The United States see's Kenya as an important ally in a volatile region facing the threat of al Qaeda-linked groups in Somalia.
"This latest incident represents a disturbing escalation of the tragic violence witnessed by these communities in August and September,” Jay carney, the White House spokesman, said in a statement.
President Mwai Kibaki has instructed security forces to prevent further deaths.
Since Kenya's disputed 2007 national elections, an estimated 1,200 people have been killed and many thousands driven from their homes.