Climate researchers are warning that the monsoons which afflict South Asia are growing in strength and are likely to continue to do so.

Low lying countries like Bangladesh are particularly at risk

Writing in the journal Science, academics in India and the United States predict that increasingly powerful monsoons will affect nearly half the world's population, sparking severe floods and devastating erosion.

Their research is published after recent torrential rains in South Asia left hundreds dead.

The team studied fossils from the floor of the Arabian Sea, where populations of a microscopic sea creature increase when monsoons - which are caused by changing winds - are strong.

They have blamed the trend on increasing levels of greenhouse gases, and rising temperatures in northern latitudes.

Dead and homeless

In the past three weeks, monsoon rains have killed more than 300 people and made millions homeless in parts of Southern Asia.

In eastern India, the authorities say more than five million people have now been affected by the current floods, caused by monsoon rain, while floods in Nepal have killed more than 200 people in the past week.

But elsewhere in the region, like north-western India, the population is suffering from the worst drought for a decade, and fears of food shortages are widespread.

This too is due to the monsoon.

Low-lying countries like Bangladesh, already threatened by sea-level rise due to climate change and by flooding and erosion, are likely to suffer even more as the monsoons become stronger, the scientists claim.