Foreign rescue teams began flying into Myanmar on Saturday to aid the search for survivors from an earthquake that killed more than 1,000 people in the impoverished Southeast Asian nation crippling critical infrastructure amid a grinding civil war.

The death toll in Myanmar was 1,002, the military government said on Saturday, up sharply from initial state media reports of 144 dead on Friday.

At least nine people were killed in neighbouring Thailand, where the 7.7 magnitude quake rattled buildings and brought down a skyscraper under construction in the capital Bangkok, trapping 30 people under debris, with 49 missing.

The US Geological Service's predictive modelling estimated the death toll could exceed 10,000 in Myanmar and that losses could exceed the country's annual economic output.

A Chinese rescue team arrived in Myanmar's commercial capital of Yangon, hundreds of kilometres from the hard-hit cities on Mandalay and Naypyitaw, the country's purpose-built capital, where parts of a 1,000-bed hospital were damaged.