Friday's deadly earthquake rattled most of Myanmar and Thailand but certain areas sustained the heaviest damage, including flattened buildings and many lost lives.

The death toll of the 7.7 magnitude earthquake on Friday rose quickly in Myanmar and was at 1,644 victims by Sunday. There were a further 3,408 people injured and 139 missing.

In the greater Bangkok area, which took the brunt of the quake in Thailand, officials said Sunday the count was 18 dead, 33 injured and 78 people missing.

Officials were still assessing the damage and any overall estimate remains incomplete. But two days later a clearer picture has emerged about the extent of the destruction.

Myanmar sits on the major north-south Sagaing Fault, which separates the India and Sunda plates, and the widespread damage runs down a wide swath of the middle of the country. The area includes Mandalay, Myanmar's second-largest city with 1.5 million people that is located near the earthquake's epicentre.

Critical infrastructure has been destroyed including the historic Ava Bridge connecting Sagaing and Mandalay, Mandalay University and various heritage sites, the International Federation of Red Cross and Red Crescent Societies said in a statement Sunday.

Little information has come out so far from areas other than the main urban areas of Mandalay city and Naypitaw and the Red Cross said the airports remain closed in both areas.

Significant damage also has been reported in the Sagaing, Naypyidaw, Magway, Bago and Shan State regions, while telecommunications outages continued to hamper emergency coordination in several regions, the Red Cross said.

The Red Cross said it has launched an emergency appeal for 100 million Swiss francs (USD 113.3 million) to assist 100,000 people in 20,000 households over the next 24 months.