At least eight people died and several others were injured on Thursday night after a matatu collided with a truck at Mlima Kiu area in Makueni on the Nairobi- Mombasa Highway.
Makueni Police Commander Barbanas Ng’eno said the accident happened at about 11 p.m.
He said eight passengers died on the spot following the head-on collision.
“We lost eight people in the tragedy. We are investigating the accident,” he said.
The matatu was headed for Nairobi from Loitoktok while the truck was en route to Mombasa, police said.
This increases to 20, the number of people killed on the highway in less than seven hours on Thursday, police confirmed.
The bodies of the deceased were moved to Kilungu Hospital while the wreckage of the vehicles was towed to Salama Police Station as investigations into the incident continued.
At least 12 people were killed in the Ndii area in Taita Taveta on Thursday evening after a matatu they were traveling in collided with a truck.
The matatu driver was reportedly trying to overtake before colliding with the oncoming truck.
This is the latest such accident to happen on the highway.
The accidents are under probe.
Dozens of people have been killed and others wounded in separate accidents in the past weeks.
The road is notorious for fatal accidents, claiming more than 3,000 lives annually according to official data.