"We want to bring together these warring communities," said regional deputy police chief Joseph Kitur, after the attack late Tuesday between the Pokomo and Orma peoples in the rural Tana River district.
The dead included at least 31 women and 11 children, the majority killed with machetes, the others burnt alive as men from the Pokomo community torched their huts.
It was not clear what sparked the attack, but the two communities have clashed before over the use of land and water resources, although the scale and intensity of the killings shocked police.
It was the worst single attack since deadly post-election violence four years ago.
"We are holding a major security meeting on the ground today, because we want to understand what the problem is," Kitur added. "We want to engage them so that we can work together in getting a lasting solution."
The Pokomo are a largely settled farming people, planting crops along the Tana River, while the Orma are largely cattle-herding pastoralists.
Police were hunting down suspects from the Pokomo group blamed for the attack, but many had escaped into the remote bush.
"Most suspects have fled from their homes after committing the attacks, but we are closing in on them," Kitur said.
The attack happened in the Reketa area of Tarassa in Kenya's south-east, close to the coast and some 300 kilometres (185 miles) from the capital Nairobi.
