Scenes of chaos and panic were reported at the Lahore airport after winter fog disrupted the flight operation and several flights were cancelled while some of the inbound flights were diverted to Islamabad and Karachi.

At least 20 flights were affected by fog, SAMAA TV reported.

The fog was so dense that visibility dropped to 100 meters. Under an international definition the visibility below 1 kilometers (1,000 meters) is considered fog.

Lahore has experienced smog this years, but officials say it was fog and not smog that disrupted flights at the Lahore Airport on Sunday.

Photos posted on social media show several airliners parked at the Lahore airport in a row.

Some flights were able to take-off but after long delays.

One passenger Sarmad Hameed tweeted that there was “chaos” at the departure lounge after flights were delayed.

He later provided an update that the travellers had been offered hotel accommodations or they were permitted to go home.

However, some international travellers says they risk financial losses because they had booked quarantine hotels at their destinations.

Meanwhile, passengers of a PIA Quetta-Lahore flight, which landed in Islamabad after being diverted, staged a protest after they were not offered food and there was no word on the alternative schedule.