Four more people have been pulled from rubble nearly 60 hours after a powerful 7.7 magnitude earthquake struck Myanmar on Friday, killing at least 1,700 people in the South East Asian country.

The survivors were rescued from a collapsed school building in the northern Sagaing region, from which a body was also recovered, Myanmar's fire service said.

Hundreds of people remain missing, with search and rescue efforts underway in both Myanmar and neighbouring Thailand.

The death toll has risen to 18 people in the Thai capital, Bangkok, where 76 workers are still missing following the collapse of a high-rise building that had been under construction.

Friday's earthquake occurred near Myanmar's second-largest city, Mandalay, along the Sagaing fault, with tremors affecting several other nations.

Although rescue efforts have been underway since Friday, and international aid is starting to reach Myanmar, there have been delays in reaching the worst-hit areas, leaving locals to attempt to dig survivors out by hand.

On Saturday night, an elderly woman was rescued in Myanmar's capital, Nay Pyi Taw, after being trapped for 36 hours under the rubble of a hospital.

Footage showed her being carried on a stretcher to a waiting ambulance, surrounded by emergency workers.