Yangon - A powerful cyclone has hit Myanmar, killing at least 351 people and destroying thousands of buildings, reports said Sunday.

Television images from the port city of Yangon, Myanmar's largest city, showed numerous trees uprooted and houses without roofs.

Tropical cyclone Nargis hit the south of the country on Saturday with wind speeds of more than 200 kilometres per hour.

Electricity and telephone lines were cut by the storm, which started in the Bay of Bengal, making communication with the former capital Yangon difficult.

British broadcaster BBC, quoting Myanmar state television, on Sunday said the latest death toll included at least 109 people who lived on the island of Haing-gyi off the south-west coast.

Myanmar's military regime has declared five regions disaster zones, including the rice-growing Irrawaddy region, Yangon, and Bago, Karen and Mon states.

Myanmar political activists based in Thailand have called on the international community to provide assistance to the country, even though the government has yet to issue a similar appeal.

"International expertise in dealing with natural disasters is urgently required. The military regime is ill-prepared to deal with the aftermath of the cyclone," said Naing Aung, secretary general of the Forum for Democracy in Burma (FDB).

"For their part, the regime must allow NGOs (non-governmental organizations) and aid agencies immediate and unrestricted access to the affected areas," said Naing Aung.

"Aid agencies and NGOs must be allowed to operate freely to provide humanitarian assistance directly to the people of Burma," he added.

The FDB is one of many Myanmar political organizations struggling to bring democracy to the country, which has been under military rule since 1962.

More than 20,000 houses were reported to have been blown down in the Irrawaddy Delta region.

The military rulers were reported to have ordered in troops to help rescue operations and clear up the chaos left by the lashing winds.

The cyclone was reported to be weakening as it moved towards Thailand. (dpa)