An earthquake measuring 6.4 on the Richter scale hit Myanmar at 8.37am on Friday. The quake was about 100 kilometres northwest of Chiang Rai's Mae Sai district, the Thai Meteorological Department's Earthquake Observation Division announced.
According to the United States Geological Survey (USGS), the earthquake's epicentre was located about 76km southwest of Kengtung township in Shan State, occurring at a depth of nine kilometres.
Three aftershocks with magnitudes of 4.1, 3.5 and 3.4 were recorded shortly after the quake.
The tremor was reportedly felt in Muang, Mae Suay and Mae Sai districts of Chiang Rai; Saraphi and Muang districts of Chiang Mai; Muang district of Lamphun; some parts of Nan; and Lak Si district of Bangkok.
The quake was also felt in Mae Hong Son in the North, as well as Udon Thani and Khon Kaen in the Northeast.
Arun Pinta, chief of the disaster prevention and mitigation office of Chiang Mai, said residents of high-rise buildings as well as staff and patients at Maharaj Nakorn Chiang Mai Hospital said they felt the tremor for about five seconds.
Mr Arun said that so far there have been no reports of damage made to reservoirs or dams in the northern province. A survey is underway in all districts to assess any potential damage caused by the earthquake.
Prasan Sangwandet, director of the Earthquake Observation Division, said the earthquake was caused by the movement of the Kengtung fault in Myanmar's Shan State.
Myanmar is lined with seimic faults and earthquakes are common.
Mr Prasan said many aftershocks of between three and four magnitude were reported after the initial quake. More aftershocks are expected to follow for one to two months.
The Thai Meteorological Department will be on alert around the clock to monitor further developments.