A Kenyan police official says his use of a plane for a personal errand did not delay the deployment of the police tactical team which ended the extremist attack in eastern Kenya where 148 people, the majority of them university students, were killed.

Kenyans are demanding answers for why it took more than 12 hours to deploy members of the police counter-insurgency unit, the Recce Company, whose officers ended the April 2 siege at Garissa University College by four gunmen from Somalia's al-Shabab Islamic extremist group.

Kenya Police Airwing Commander Rodgers Mbithi said in a statement to police investigators that his decision to allow his daughter-in- law and her children to be flown from Mombasa to Nairobi did not delay the movement of the Recce Company from Nairobi to Garissa.