Area police boss Charles Muthui said the driver of a canter which was headed to Nairobi, his loader and a passenger in the second lorry died following the incident.
He said the accident occurred after one of the lorries tyre burst.
"The driver of the trailer escaped but a passenger who was on board was burned beyond recognition," Muthui said.
The bodies were taken to Machakos Level 5 Hospital mortuary.
The Star/By MUTUA KAMETI