Three people died on Saturday when the matatu they were travelling in overturned at Mbuvo on Wote-Makindu road in Makueni County.
Four people, who survived, were rushed to Makueni County Referral Hospital for the treatment of their injuries.
Witnesses said the driver of the passenger service vehicle lost control while heading towards Makindu township. The vehicle veered off the road and overturned.
Witnesses said the matatu was carrying 16 passengers, instead of 14 or less, considering restrictions to contain the spread of the Covid-19 pandemic.
"The driver lost control of the vehicle after one of its rare tyres burst while he attempted to overtake," one of the witnesses said.
The bodies were taken to the Makueni hospital mortuary.