Recent clashes between the Myanmar military and the ethnic Karen resistance movement across the border have prompted more than 5,000 people from Myanmar to flee into Tak's Mae Sot district, authorities said.
Tak governor Somchai Kitcharoenrungroj said that as of Sunday, 5,358 villagers from Myanmar had crossed the Moei River to seek refuge on Thai soil.
Security officials have also extended humanitarian assistance to refugees sheltering in Mae Sot and Phop Phra districts, where those injured are being treated by medics, he said.
As the clashes along the Thai-Myanmar border escalate, reports of stray bullets and grenades from across the border have also increased in Mae Sot and Phop Phra districts.
In response, border authorities are warning conflicting parties to ensure their clashes do not spill over into Thai territory.
Tak's provincial administration have also warned residents not to approach the border, and ordered authorities to beef up patrols along the frontier.
Fearing they might get hit by stray bullets from Myanmar, some residents have chosen to leave their homes for the safety of their relatives' houses, schools and temples further from the border.
The clashes between Myanmar and Karen National Union (KNU) troops have cooled down after heating up at the start of the weekend, observers say.
On Saturday night, Myanmar troops fired heavy weaponry at KNU positions in Mae Tod Taloh village, in Myanmar's Myawaddy province, opposite Ban Don Chai Rim Moei in Tak's Mae Sot district.
The military also launched airstrikes on the KNU stronghold, causing over 1,000 Myanmar villagers to flee into Thailand for shelter.
They were taken to Ban Mae Ku Mai Tha Sung stadium, authorities said.
As of Sunday, 167 refugees from Myanmar were still sheltering at Ban Ku Luang, after 59 decided to return, sources said.
Meanwhile, 1,302 people remained at the shelter at Ban Mae Tao Klang school, while 1,511 remained in Khok Wua Maha Wan Moei.