SPOT THE BABY BUNDLE BEYOND THE BAGS: Fog envelops the Serampore railway station platform on Wednesday morning. Picture by Pradip Sanyal

Pakistani passengers on board a Dhaka-Karachi flight that was diverted to Calcutta because of fog got a taste of both hospitality and hostility when they were told that their plane could land but they couldn’t.

None of the 210 passengers on the Pakistan International Airlines was allowed to disembark during the 10 hours that the craft spent at the city airport waiting for the fog over the Bangladesh capital to clear.

The passengers — it couldn’t be confirmed whether all 210 were Pakistani nationals — were not allowed to disembark because security regulations stipulate that air travellers from that country must clear immigration either in Delhi or Mumbai.

The flight, which landed in the city at 1.20am on Wednesday, finally took off for Dhaka around 11.45am.

Passengers aboard three other Dhaka-bound international flights diverted to Calcutta couldn’t disembark either, but because of other reasons.

“They were all international passengers in transit and would have had to clear immigration even if they disembarked for a while. We were looking to clear the flights for take-off as soon as visibility improved and didn’t want any further delay,” a senior official of the Airports Authority of India said.

Calcutta also had its share of fog hits. Low visibility at the city airport stalled flight operations for around four hours in two phases, delaying 15 flights.

A diverted Kuwait-Dhaka flight with 209 passengers on board landed at 1.05am and took off at 11.35am. Air Arabia’s Sharjah-Dhaka flight, carrying 156 passengers, landed at 2.05am and took off at 11.40am.

A Biman Bangladesh Karachi-Dhaka flight with 95 passengers on board landed at 5am and took off at 12.53pm. Two flights from Calcutta to Dhaka were also delayed because of fog.

“Visibility was around 100 metres between 5am and 7am,” an official said. “It improved after that and eight flights took off. But visibility dropped again to below 100 metres around 8am and remained that way till 10am.”

Passengers on flights readying for take-off before visibility dropped for the second time suffered the most.

“Most of them were either going through security check or boarding when the light worsened. One flight was on the main runway but had to be brought back to the holding line on the taxiway. It waited there till visibility improved,” an official said.

A JetLite flight from Delhi hovered over the airport for a while because the pilots didn’t want to take the risk of landing till the fog had cleared completely.

Air India’s Bangalore-Calcutta flight, which was scheduled to land at 8.30am, managed to touch down at 10.20am.