The Kenyan military has joined police units to drive out attackers from the troubled Laikipia Nature Conservancy in the Rift Valley.

Armed pastoralists have invaded the private protected area and have torched homes as well as moved large herds of animals to graze on maize fields.

Police say the illegal herders are mostly from neighbouring Baringo county.

At least six people have been killed in the last week and more than a dozen have died in a month.

According to local reports, seven houses were destroyed overnight, including two which belong to police reservists.

Affected locals are suggesting there is a deliberate effort to drive some communities out of the region.

Hundreds of people have been forced from homes where some have lived for decades in incidents which have been linked to growing competition over land and water.

Two politicians, including a member of parliament, were arrested two days ago on suspicion of incitement. They have not commented on the charges.