Lamu County Commissioner Irungu Macharia confirmed the incident. The bus came from Mombasa and was headed to Lamu.
There were no details on casualties or injuries by press time.
"I have heard of such an incident but I am headed to the scene...I am also liaising with officers on the ground. Details on injuries, casualties or the bus company are yet to be established but I'll give details soonest," Mr Macharia told the Nation.
More to follow.