A bomb explosion at a bus station in Kenya's capital Nairobi has killed three people and wounded 23 others. The blast occurred during a security search before the coach's planned departure for the Ugandan capital Kampala.Kenyan police chief said “an explosive device” in a piece of luggage was the source of the blast. The blast left a blood-stained scene, although the red Kampala Coach bus appeared to have suffered limited damage. An official with Kampala Coach Ltd said the attacker was among those killed by the blast.