An intensifying cyclone churned north toward Bangladesh on Monday after heavy rain in Sri Lanka and thunderstorms in eastern India killed almost 200 people, with more torrential downpours forecast.

Impoverished Bangladesh, hit by cyclones every year, warned that some low-lying coastal areas were "likely to be inundated by a storm surge of four to five feet (1.2 to 1.5 metres)" above normal and raised the storm danger signal, on a scale of one to 10, to seven.

Cyclone Mora was expected to make landfall on Tuesday morning.