The first tremor hit 16 km northwest of the city of Sagaing at a depth of 10 km at about 12:50 pm (06:20 GMT) on Friday, USGS said.
The AFP news agency reported from Myanmar’s capital Naypyidaw that roads were buckled by the force of the tremors and chunks of ceilings fell from buildings.
An officer from the Myanmar Fire Services Department told the Reuters news agency, “We have started the search and going around Yangon to check for casualties and damage. So far, we have no information yet.”
Social media posts from Mandalay, Myanmar’s ancient royal capital that is at the center of its Buddhist heartland, showed collapsed buildings and debris strewn across streets of the city.
In neighboring Thailand’s capital Bangkok, startled residents poured out of high-rise buildings. Witnesses said the tremors were forceful enough to send water sloshing out of pools, Al Jazeera reported.
There are reports of 43 construction workers being stuck under the rubble of an unfinished 30-storey building that collapsed in the Chatuchak area of Bangkok.
Some metro and light rail services were suspended in Bangkok.
Thai Prime Minister Paetongtarn Shinawatra announced a state of emergency in her country.
Earthquakes are relatively common in Myanmar, where six strong quakes of 7.0 magnitude or higher struck between 1930 and 1956 near the Sagaing Fault, which runs north to south through the center of the country, according to the USGS.
A powerful 6.8-magnitude earthquake in the ancient capital Bagan in central Myanmar killed three people in 2016, also toppling spires and crumbling temple walls at the tourist destination.