The death toll from a tropical storm that lashed parts of northeastern Madagascar last week has climbed to 18, the government's risk and disaster management office announced Friday.

Another 19 people are missing after the storm flooded several districts and cut roads linking them to the capital Antananarivo.

An updated tally sent to AFP by Faly Aritiana Fabien, a senior official at Madagascar's National Risk Management Office, showed two more deaths in addition to the previously announced 16.

More than 55,800 people were affected by the floods, many of them displaced from their homes.

Storm Cheneso made landfall on January 19, packing winds of up to 110 kilometres (68 miles) per hour and triggering downpours.

It is the first tropical storm of the current cyclone season in southern Africa, which typically runs from November to April.