Car bomb kills four in Kenyan capital

A controlled detonation by bomb disposal officers in Nairobi.<br/> <br />Four people were killed here earlier, when a car bomb exploded outside a police station.<br/> <br />The Interior Ministry said police had stopped the vehicle at traffic lights when the bomb went off.<br/> <br />It was not immediately clear who was behind the attack.<br/> <br />But authorities say they are struggling to contain a surge in bomb and gun attacks, and blame Somali Islamist militants for recent unrest.