Three people were killed after a sand mine caved in at Kwa Muvai River, Makueni county on Tuesday.
Two others were injured and rushed to a hospital.
County commissioner Mohammed Maalim said the miners were trapped on Monday night.
He said the miners were retrieved by residents who heard a strange sound at the site.
"It is illegal to mine sand at night. It is even dangerous to access the mines at that hour when it's raining," Maalim said.
The lorry being used by the miners was impounded by police.
