Two people were feared dead after they were swept away by mountain runoff triggered by rainstorms in Lamphun's Mae Tha district on Monday night, local officials said yesterday.
The incident occurred in Ban Huay Hom Nok village, where runoff flooded the area and damaged several homes.
According to residents, the runoff struck late at night, catching them off guard.
A relative of the missing individuals said her aunt and uncle were trying to gather their belongings when the water was still only knee-deep.
Within minutes, however, the muddy floodwater rose rapidly and swept them away.
Lamphun governor Wiwat Inthaiwong, who inspected the site yesterday with local officials, said eight houses were damaged in the floods, with the two residents reported missing and feared dead.
Meanwhile, a weather warning has been issued for those travelling to Sao Hin in Mae Hong Son's Mae Sariang district following heavy rain that caused rivers to swell.
Local authorities said that Sao Hin has several streams, and if persistent rain occurs, it could trigger flash floods and pose serious risks to residents and visitors in the area.
The Office of National Water Resources (ONWR) has also issued an alert for flash floods, runoff and mudslides until tomorrow for 23 provinces across the country.
Most of the provinces that stand to be affected are in the northern and southern regions, including Chiang Mai, Chiang Rai, Mae Hong Son, Lampang, Ranong, Surat Thani, Krabi, Songkhla, Yala, and Narathiwat.
State agencies have been instructed to prepare emergency response plans and stay on high alert.