Four people were on Friday morning beheaded by suspected al Shabaab militants in Maleli village, Lamu West.
Lamu Operation Linda Boni director Joseph Kanyiri said three bodies were found by villagers.
The fourth was discovered in a bush by police. Kanyiri said the attack was carried out at 12.30am.
The attackers also torched several houses in the village before disappearing into a bush.
Kanyiri said officers had been dispatched to pursue the attackers, who are said to have fled back into a bush after the incident.
The four killed are said to have been guarding their farms from invasion by herders who graze their livestock in farms. Kanyiri said investigations are going on.
“We aren’t sure who is responsible, but we have zeroed in on either al Shabaab or they were killed due to conflicts of pasture between herders and farmers. The killings are gruesome and similar to what happened in Jima village last month,” he said.
During the July 8 Jima attack, nine people were beheaded.
Kanyiri has also ordered all herders to remove their animals from Boni Forest in the next 48 hours.
He said anyone who disobeys the order will be considered a terrorist.
Kanyiri said many of those posing as herders are suspicious, since their activities are closely related to those of al Shabaab.
He said it is hard to comprehend how the herders, who graze their livestock in the forest, claim not to see any attackers or even their hideouts.
Kanyiri said police who were pursuing the attackers, discovered that most of the footprints led to the homes of known herders.
“They will explain to us why the footsteps didn’t lead anywhere else,” he said.
Kanyiri said he is aware some locals are helping al Shabaab by giving them food and information on the movement of the police.
“The so-called herders must give the security a latitude to operate and deal with al Shabaab. We want them all out in the next 48 hours.We need to deal with this matter decisively so that we end it once and for all,” he said.