A train carrying fuel derailed in Changamwe, Mombasa on Saturday night, police said.
The train was carrying 250,000 litres of super petrol when it rolled at 11.35pm, police said in a statement.
Seven wagons of the train are said to be submerged in the ocean.
A section of the Makupa Causeway was closed indefinitely in both directions affecting Moi International Airport and Standard Gauge Railway users.
Firefighters and police remain on scene.
No one was injured or killed in the incident.