At least 32 have been killed in clashes between Kenya's Pokomo and Orma communities in the country's southeastern Tana River region, Kenya Red Cross officials and police say.
The violence began on Friday dawn when the Pokomo raided Kipau village belonging to the Orma.
Forty-five houses were set on fire during the attack, Nelly Muluka, a spokesperson for the Kenya Red Cross, said.
Athony Kamitu, a police officer leading operations to prevent further clashes, said that the Pokomo, mainly subsistence farmers, raided a village of the semi-nomadic Orma herding community.
The raiders were armed with spears and AK-47 rifles, Kamitu said.
'Hacked to death'
Al Jazeera's Nazanine Moshiri, reporting from Mount Kenya region, said "the victims were shot, their houses were burnt [and] some of them were hacked to death".
"There are many people who were injured as well. Kenya Red Cross says they managed to evacuate 16 of the most seriously injured to Malindi, a town on the coast, but they are still searching the area for more victims."
Our correspondent said the two communities were fighting over land, adding that the Tana River region, about 690km from the capital, Nairobi, is a semi-arid area with scarce water and grazing land.
"The Ormo on one hand are nomads and then there are the semi-pastoralists who are the Pokomo tribe. Now they have been at odds for decades," she said.
The conflict could also have been triggered by politics, our correspondent added.
Kenya is due to hold presidential elections in March 2013 and political boundaries in the Tana River region have been changed, sparking anger among the communities, our correspondent said.
Dhadho Godana, a member of parliament from the region and Yusuf Hajji, the defence minister, have been accusing each other of involvement in the fighting.
The two have testified before a commission of inquiry led by a High Court judge investigating the clashes.
The Standard newspaper in Nairobi reported that the commission is due to compile its report after receiving testimonies from some 95 witnesses and suspects.
At least 110 people were killed in clashes between the Pokomo and Orma in August and September.
Violence after Kenya's last general election, in late 2007, killed more than 1,000 people and officials are working to avoid a repeat during March's presidential election.
However, episodes of unrest around the country are raising fears that pockets of the country will see violence during the voting period.