Flights were cancelled at airports in northeast Thailand after the region was hit by thick fog on Friday.

Footage shows the heavy haze reducing visibility at the Khon Kaen International Airport on January 13.

The poor weather conditions triggered the cancellation of five flights to Khon Kaen province as temperatures dropped to 19 degrees Celsius.

Officials said that at least four flights from Bangkok to Khon Kaen were cancelled mid-air after the planes could not land due to low visibility. They travelled back to either Don Mueang International Airport or Suvarnabhumi Airport.

Another morning flight from Chiang Mai to Khon Kaen was also cancelled.

Four airports - Khon Kaen Airport, Udon Thani Airport, Ubon Ratchathani Airport, and Sakon Nakhon Airport - in the northeast were temporarily closed due to the fog.

Some 700 passengers at the Phuket, Don Mueang, and Suvarnabhumi airports had also been affected by the cancellations, local media reported.

Manoon Dor-oy, deputy director of the Northeastern Meteorological Centre, expected the fog would be disappeared from 11 am but the sky might still be cloudy.

Addressing the weather problem, Teerasak Teekayupan, mayor of Khon Kaen municipality, warned people to take care of their health and children.

He said that thick fog affecting transport in the region was 'rare'.