He said the officers and firefighters rushed to the scene to contain the situation.
"There are no injuries and officers are on the ground," Kimathi said.
By the time of going to press, the police boss noted that the fighters were still battling out the fire.
Passengers who were evacuated safely were standing along the road in shock as they watched firefighters trying to put out the fire.
Locals who milled around the scene were kept at a distance by the officers.
Kimathi said they have launched an investigation into the incident.
Check out photos of the bus below taken by Daniel Ogendo.
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