The Civil Aviation Authority of Thailand has banned all flights with Covid-19 infected passengers from transiting through Thailand after China banned two flights from here.

CAAT director-general Chula Sukmanop spoke of the new measure on Thursday in response to the report that the Chinese government temporarily banned the services of Thai AirAsia X and Thai Lion Air for carrying some passengers infected with the coronavirus disease to China.

Under the new requirement, he said, airlines must sell tickets only to passengers who had Covid-19-free certification for flights transiting through Thailand.

The requirement applies even though passengers do not get off the planes in the country, Mr Chula said.

Most international flights at this time were those chartered to carry people back to their homeland.

Media reported that China banned both airlines for a week after some passengers on their flights on July 10 and 13 were found to be infected. The flights were from Kuala Lumpur and Jakarta via Bangkok's Don Mueang airport to Tianjin and Guangzhou, China. 

Taweesilp Visanuyothin, spokesman of the Centre for Covid-19 Situation Administration, said both chartered flights made stopovers in Thailand, probably for the rights to fly to China since direct routes from Kuala Lumpur and Jakarta are still banned, he said.

He confirmed that the passengers on both flights remained on their planes during the stopovers. About 5-6 passengers each on the two flights had Covid-19, he said.