The victim and a relative were allegedly drunk when the incident occurred.
Villagers in Bonchari, Kisii County Friday spent several hours in search of the body of a man who drowned in River Riana on Thursday night.
Mr Mayieka Mose was crossing a rickety bridge near Daraja Mbili market at night when he slipped and fell into the swollen river.
A relative, Albert Mogambi, who was with him when the incident happened reported the matter to the police and a frantic search started immediately.
The two were allegedly drunk when the incident occurred.
By Friday afternoon, the search mission that also involved relatives was extended to the banks of Nyakomisaro River.
"We had been searching since morning but were unable to locate him. We are hoping for the best," said John Kimbo, a relative who had joined in the search.
He appealed to government to assist with divers to help them in the search.
Kisii County disaster coordination boss Julius Tinega said rains pounding the area had hampered the search.
"The search has been intermittent due to the [heavy] rains that halt search operations," he told the Nation.
The incident came three days after a boda boda rider drowned in river Nyakomisaro as he crossed over to Jogoo Estate in Kisii Town.
Mr Tinega cautioned residents against crossing swollen rivers especially on rickety bridges.
He also asked those residing in areas prone to mudslides move to safer places.