A 4.6-magnitude earthquake occurred off the southern tip of Koh Yao Yai of Phangnga province early Wednesday, with reports of cracks on a local mosque and a pier. No casualties were reported.
Authorities were inspecting damage to the structures in tambon Phlu Nai in Koh Yao district, which is near the quake epicentre.
The quake occurred at 4.18am with the epicentre at 4km under the sea. The tremor could be felt in Phangnga and in the surrounding provinces of Phuket and Krabi, according to the Meteorological Department's Seismological Bureau.
The quake was about 18km southeast of Phuket's Muang district. A shaking sensation lasting five to 10 seconds was reported over much of Phuket.
The bureau said there was no danger of a tsunami.
Local people on Koh Yao Yai did not move to higher ground as many of their homes already sit on hillsides.
However, no early warning tower has been installed to alert tourists on the island despite it being a major tourist spot.
Tambon Phlu Nai mayor said residents have called for an early warning tower to ease their concerns.
In Krabi, the quake was also felt by people living in high buildings on Aow Nang beach and Khlong Muang beach in central Krabi.
People on Koh Phi Phi in tambon Aow Nang rushed to higher ground for fear of a tsunami. Authorities issued announcements telling them not to worry.
Phuket governor Nisit Chansomwong said he instructed local authorities to check sea levels, and they found the ebb and flow was normal and there was no underwater damage caused by the tremblor.
He said Phuket has an efficient earthquake monitoring system, with its 19 tsunami early warning towers undergoing regular tests by the National Disaster Warning Centre.
Government spokesman Yongyuth Mayalarp said agencies involved in monitoring earthquakes in Thailand have confirmed Thailand stands little chance of experiencing a major quake of more than magnitude 7, since the 14 fault lines in the country are all small.