Passengers were left concerned when a thick fog filled the cabin of the aeroplane.

Travellers had to cover their noses as smoke billowed from the Airbus A330 while they prepared for take-off at Ninoy Aquino International Airport in Manila, the Philippines.

Footage shows an EVA Air flight attendant wearing a yellow inflatable vest carefully walking down the aisle on October 26.

Passengers aboard Flight BR278 to Taipei, Taiwan, expressed concern, while others could be heard laughing at the unusual sight.

Officials clarified that the so-called 'smoke' was harmless water vapour, formed when cold, dry air from the air-conditioning system mixed with the warm, humid air inside the cabin.

This effect is often more pronounced due to the greater temperature difference between the cabin and the outside air in tropical regions such as the Philippines, Thailand, and Malaysia.