Bangkok and at least three provinces were shaken by two moderate earthquakes centered near the southern coast of Myanmar on Monday morning, the Earthquake Observation Division reported.
The tremors caused no damage and no injuries were reported.
The division said the first quake, 5.3 on the Richter scale, was detected at 9.05am Thailand time. Its epicentre was 10 kilometres underground near the southern coast of Myanmar, 247km southwest of Thailand's Mae Sot district in Tak province.
The second, 3.2-magnitude tremor was 10km deep, also near the southern coast of Myanmar, at 9.18am Thailand time.
People in Bangkok, Chiang Mai, Lampang and Nonthaburi sent about 40 reports to the division saying they felt the quakes and suffered nausea for short periods. Most of them were in buildings in Bangkok.
The Department of Mineral Resources attributed the quakes to the movement of the Sagaing fault in the Andaman Sea.
Several high-rise buildings in Bangkok were evacuated.
The department said there were no early reports of damage caused by the quakes.
Thailand Structural Engineers Association president Amorn Pimanmas said the moderate earthquakes on Monday had no impact on the structures of buildings in Bangkok, but they could shake because the soft soil foundation under the capital amplified vibrations from the tremors.
Bangkok deputy governor Wisanu Subsompon said structural impact could occur from vibrations measuring 25 milli-G or more (a measurement indicating how violently the ground shakes).
The quakes on Monday morning caused vibrations of only two to four milli-G, recorded at nine buildings in Bangkok equipped with vibration sensors.
A huge earthquake early last year caused building vibrations at the level of 123 milli-G, he said, referring to the Myanmar earthquake which led to the collapse of the 33 storey State Audit Office tower, which was nearing completion, in Bangkok on March 28, 2025.
