'The storm surge was the major cause of the disaster,' said Mr Dieter Schiessl, director of the World Meteorological Organisation's disaster risk reduction unit.

Myanmar's meteorology department started to send out warnings six days before Cyclone Nargis hit the coast, based on information from World Meteorological Organisation offices around the world, Mr Schiessl told reporters in Geneva, where the agency is based.

The wind speed was correctly forecast, he said. But 'the problem was the lack of a radar network to monitor the storm', Mr Schiessl said.

Myanmar said it had warned the population in newspapers and in television and radio broadcasts, he said.

But he added that his organisation had been unable to verify how the warning information was used by the authorities and 'what really reached individuals'.

MASSIVE DAMAGE -- PHOTOS: AP Nasa satellite photos show the stricken area of Myanmar before and after Cyclone Nargis. On April 15, rivers and lakes are sharply defined against a backdrop of vegetation and fallow land. The Irrawaddy flows south through the left-hand side, splitting into tributaries to form the deep blue-green wetlands near the shore. ... more

Tropical cyclones hit Myanmar only once in 40 years on average, a reason that preparedness may not have been a top priority for the country, he said.

The international weather organisation is ready to help Myanmar set up a radar system to better monitor future cyclones, Mr Schiessl said, adding that funds were needed for this.

ASSOCIATED PRESS