Flash floods swamped villages amid heavy rain in southern Thailand.

Overnight rains battered homes in Phatthalung province on December 18 evening, triggering floods that lasted until the following morning.

The Khao Sai Wildlife Sanctuary was swamped, with the water running off towards low-lying areas.

Local media reported that hundreds of families and their belongings were evacuated to safety as some districts saw rainfall of up to 112mm in 12 hours. Sandbags were also placed around their homes to mitigate the flow of water and prevent further flooding.

Several roads were also affected by the deluge that caused traffic chaos along the Phatthalung - Hat Yai area. Drivers were advised to look for alternative routes.

Phatthalung authorities have warned remaining villagers in the lowlands to brace for more flash floods and torrential rain.

Thailand's Meteorological Department warned of 'four metre high waves' battering regions along the eastern-facing coastline. Officials said the heavy rain would continue until December 20 in Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala and Narathiwat along the border with Malaysia.