At least 610 people are confirmed dead after Cyclone Sidr hit southern Bangladesh.
However, local Red Crescent officials believe the actual death toll could exceed 1,000.
The eye of Cyclone Sidr crashed into the coast last night before sweeping north towards the capital Dhaka.
Most of the deaths were caused by trees crushing homes.
Wind speeds of 220-240km/h have been recorded in what officials described as one of the biggest storms in years. Telephone lines and power supplies have also been cut.
Hundreds of thousands of people spent the night in special shelters in a bid to avoid the massive casualties of previous major cyclones.
Experts have described Sidr as similar in strength to the 1991 storm that triggered a tidal wave that killed an estimated 138,000 people.
Another cyclone in 1970 killed up to half a million people.
Bangladesh has since set up an early warning system and a network of shelters in vulnerable coastal areas.
Some 100,000 villagers in coastal areas of West Bengal are now returning home despite heavy rain after being evacuated to 69 temporary camps.
The storm, which reached Dhaka early this morning, weakened overnight and was progressing through the northeastern state of Sylhet.
Minister of State, Michael Kitt, has announced €500,000 in relief aid in the aftermath of a cyclone.
