At least eight people have been killed in a road accident involving a matatu and a truck on the Nairobi-Mombasa highway.

Traffic Commandant Samuel Kimaru says the accident occurred when a matatu from Loitoktok hit a stationary lorry at Kyumvi area, in what has been blamed on bad weather hampering visibility.

Four other passengers sustained serious injuries and have been rushed to nearby hospitals for emergency treatment following the 2 am accident.

As a result of the accident, Inspector General of Police Joseph Boinnet is urging motorists to exercise extra caution on roads due to poor visibility occasioned by bad weather in most parts of the country.

"We are appealing to motorists to be extra cautious particularly during this period of heavy rains that is hampering visibility," the IG said, "our drivers should be very cautious."

Areas most affected include sections of Mombasa highway, Narok-Mai Mahiu road, Thika-Garissa road, and several parts of Eastern region among others.

A section of the Narok road was recently cut off due to heavy rains in what geologists linked to seismic activity on the greater Rift Valley.