The occupants of the Mazda bus, a commercial vehicle, were coming from Ogido in Ogun State and heading to Beere in Ibadan, to attend a Wolimat programme of a family member.
It was also gathered that most of the occupants were dressed in a uniformed ankara for the occasion.
The propeller of the bus, according to the eyewitness, pulled out on the motion and hit the fuel tank, catching flame in the process.
The driver of the bus, in an attempt to save the situation, veered off the road and hit a hip of sand by the side of the road.
The driver and two passengers at the front escaped, but others were not so lucky, as the side door was locked.
The occupants were reported to have struggled with one another in a bid to escape, while the 11 casualties, comprising eight adults and three children, were burnt to death.