One patient was treated and discharged while another was transferred to a private hospital at the family's request after they were involved in the accident at Salgaa along the Nakuru - Eldoret highway early Tuesday morning. Two other passengers who were critically injured are still undergoing treatment.
The four had been rushed to the Rift Valley Provincial General Hospital for treatment after they were injured in the 1 am accident that claimed the lives of 11 passengers.
The accident involved a 14-seater matatu, a truck and a bus. According to eyewitnesses, the matatu that was headed to Nakuru was overspeeding and tried to overtake the truck, but instead rear-ended it as the driver avoided an oncoming bus.
The bus tried to avoid the matatu, but instead hit it as the matatu swerved onto the bus's lane after the initial crash with the truck.
10 people who were in the matatu died on the spot while one other passenger died while being rushed to Rift Valley Provincial General Hospital to receive treatment.
In a separate accident at Ihindu near Naivasha, three people died after a speeding bus collided head on with a matatu in an accident that also involved a saloon car and a lorry.
Witnesses say the Nairobi-bound bus hit the matatu headed for Naivasha causing it to roll before hitting a tree. The driver and a passenger died on the spot while another passenger succumbed to his injuries while being rushed to hospital.
The two accidents come in the wake of the 2012 Traffic Act which stipulates tough penalties for those guilty of causing accidents. The new traffic laws treat deaths caused through careless driving as murder.