At least 42 officers were killed when cattle rustlers ambushed police, officials say, after more bodies were found on Monday.The attackers used sophisticated weapons such as anti-personnel bombs and rocket-propelled grenades, one local official said.A religious leader told the BBC that villagers feared being caught up in further revenge attacks.This is the most deadly attack on the police in Kenya's history.Internal Security Minister Katoo ole Metito vowed to bring those responsible to justice, the Standard newspaper reports.The officers were attacked in Baragoi in the northern Samburu County as they attempted to recover stolen cattle. Locator map"They were ambushed by attackers bearing sophisticated weapons, including machine guns," Rift Valley provincial commissioner Osman Warfa told the Reuters news agency.The religious leader, who did not want to be named, said the situation was "tense, with heavily armed security personnel patrolling villages"."We fear the anger of these security people could fall on innocent civilians, as those who may have killed the policemen are nowhere now," he said.A security source who said that 42 bodies had been found told the BBC that the final death toll could be even higher.Police spokesman Eric Kiraithe said three of the attackers had been killed, while nine injured officers remained in hospital.The local Samburu and Turkana communities often steal cattle from each other, and clash over grazing rights and access to water points.A similar attack, in which 12 people were killed, took place nearby two weeks ago, Kenyan media report.