
The crash occurred after midnight in the Salama area when a truck driver attempted to overtake another truck but failed, swerved and collided with several vehicles, including a van carrying pilgrims, according to police.
The truck driver and at least 12 passengers in the van died at the scene, police said.
The pilgrims were travelling to a prayer site in Nakuru County, west of Nairobi, said Martin Kivuva, Archbishop of the Catholic Archdiocese of Mombasa.
It was not immediately clear how many pilgrims were travelling in the van or whether anyone survived the crash.
Road accidents remain a major problem across Africa, with poorly maintained vehicles, speeding and poor road conditions often cited as contributing factors, reports UNB.