The authorities in Tanzania on Thursday began rationing water in the commercial capital Dar es Salaam because of a drop in the River Ruvu's levels.

It is dangerously low, leaving the city with a deficit of nearly 166 million litres of water a day.

People in Dar es Salaam will be without piped water for 24 hours on alternate days until the water levels improve.

Dar es Salaam Regional Commissioner Amos Makalla said the water rationing was a result of a prolonged dry spell.