Passengers at some of the UK's busiest airports are being warned of flight disruptions due to heavy fog.

It comes after 20,000 people were affected by airport disruption on Friday.

Poor visibility means temporary air traffic restrictions have been put in place at Gatwick.

Sunday is expected to be the airport's busiest day during the holiday period, with 769 flights planned.

Travel expert Simon Calder said airlines are obliged to take care of passengers if their flight is cancelled.

"Every airline that cancels a flight is obliged to find for its passengers an alternative flight as soon as possible," he said.

"The airline must also provide meals and, if necessary, accomodation until [passengers] can get where they need to be."

At Gatwick on Saturday, 54 flight arrivals have been delayed between 12pm and 2.30pm and 57 departing flights have been delayed. One incoming flight has been cancelled.

At Heathrow, 38 flight departures scheduled to leave between 12pm and 2.30pm have been delayed, and two have been cancelled.

At Manchester airport, 17 departures and 31 arrivals have been delayed between between 12pm and 2.30pm.

The thick fog will continue on Saturday according to the Met Office, with some areas seeing visibility reduced to just 100 metres.

Main image: Plane on final approach to Luton Airport in fog Bedfordshire. Image: Davlan / Alamy. 2003