On Saturday, the Principal Secretary ASALs and Regional Development Kello Harsama, said over 20,000 families across the Coast required humanitarian aid including food and shelter.
"To cushion those affected, we have released rice, beans, 300 pieces of mattresses, and other foodstuff for them. The government is ready to support those affected," said Harsama.
Those missing include two Kenya Revenue Authority officers whose vehicle was swept away by the raging floods into the Ramisi River on the busy Mombasa-Lunga Lunga Highway on Friday.
KRA Southern Region Regional Coordinator Lawrence Siele said an intensive search and rescue operation by a multi-agency team was underway.
"The two officers were traveling to Mombasa from Lunga Lunga, where they are stationed when the accident happened. The vehicle was swept by floods at Ramisi River in Kwale County," he said.
In Changamwe, Mombasa, a student died after she reportedly stepped into the electrified flood by a faulty electric wire.
On Friday, Kenya Power disconnected electricity to most parts of Mombasa to avert disasters.
Mombasa Governor Abdulswamand Nassir said Bamburi, Bombolulu, and Utange were the most affected areas. "Parts of Mombasa like Utange, Old Town, and Bofu could have sunk into the ocean if we did not have a working drainage system. The intensity of the rain has never been experienced in the county," said Nassir.
He added: "Working hours at three hospitals are extended to deal with emergency cases. We have also introduced food rationing for affected families."
Heavy rains have been pounding the Coast for the third day, with the weatherman predicting it to continue until early next week.