The jihadists are reported to have addressed the congregation for two hours before disappearing into a nearby forest.

They criticised Kenyan authorities and warned people not to pass intelligence to the security forces.

Last month al-Shabab killed at least 148 people at a university in Garissa.

Police commander Caleb Matoke told The Standard25 militia took part.

The group is based in Somalia but is also active in Kenya.

Al-Shabab says it has been at war with Kenya ever since Kenyan forces entered Somalia in October 2011 in an effort to crush the militants.