Hundreds of passengers were delayed when flights were cancelled due to thick fog across northeast Thailand this morning.

Footage shows people waiting for their planes at the boarding gate inside the Khon Kaen International Airport. Four other airports in the region were also affected.

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.

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'.