Cyclone Idai death toll surges past 600, 'worst yet to come'

Stranded: Flood victims gather on the roof of a house in Buzi. [AFP]

The death toll from a powerful cyclone that pummelled swathes of southern African countries, flooding thousands of square kilometres, on Saturday surged past 600 as diseases stalked tens of thousands of survivors.

At least 417 people have died in Mozambique, according to government, bringing to 676 the total deaths when combined with those from neighbouring Zimbabwe.