Cyclone Batsirai killed at least six people and displaced nearly 48,000 when it struck Madagascar overnight, the country's national disaster management agency said on Sunday.

Cyclone Batsirai weakened overnight, but not before wreaking havoc in the Indian Ocean island nation which is still reeling from a deadly tropical storm earlier this year.

The eastern district of Mananjary was lashed with heavy rain and wind before the cyclone made landfall, forcing local residents to weigh down their flimsy corrugated iron roofs, an AFP correspondent said.