Four relatives were on Tuesday killed in a road crash at Kadongo Trading Centre in Rachuonyo, Homa Bay.
Six survivors were admitted to Rachuonyo South Sub-County Hospital in critical condition, officials said.
The crash, which happened along the Kisii-Ahero highway, involved a matatu that was ferrying mourners from a funeral in Dol Kodera in Oyugis, and a trailer.
Three people died on the spot and another died while being treated in hospital.
Witnesses said the trailer skid on the road as the driver avoided hitting a vehicle that was entering the highway from a petrol station.
The oncoming matatu rammed into the trailer killing three passengers on the spot.
Rachuonyo East Deputy County Commissioner Kiprotich Rop said injured passengers were rushed Hospital.
Following the accident, there was a huge traffic snarl-up on the highway. Motorists were forced to use alternative routes.
The bodies of the dead were taken to Rachuonyo South County Hospital mortuary.