Dozens of flights were cancelled at London's Heathrow Airport on Thursday after fog blanketed the British capital.
A Heathrow spokeswoman said that 78 inbound and outbound flights had been axed at the west London hub.
She added that she expected the fog to lift by Thursday evening.
It was the second day running of flight disruptions at Heathrow, one of the busiest airports in the world, following delays and cancellations on Wednesday due to anti-austerity strikes in mainland Europe.
The fog also affected services at several other airports in southeast England, including London City, Norwich and Southampton.