At least five people were killed when a grenade ripped through a minibus in Nairobi's Somali-dominated Eastleigh neighbourhood on Sunday, a Reuters witness and police said.
"I saw bodies ripped apart," the Reuters photographer said.
The force of the explosion tore apart the vehicle's roof and seats and shattered the window of a nearby cafe.
Two other cars were damaged, the photographer said.
Kenya has suffered a string of deadly attacks in its capital Nairobi, the southern port city of Mombasa as well as the eastern garrison town of Garissa over the past year.