Three flights of Pakistan International Airlines (PIA) scheduled to land in Karachi were diverted to other cities due to heavy fog on Friday morning, leaving relatives of passengers in a state of confusion.

Flights PK-214 from Dubai to Karachi and PK-307 from Lahore to Karachi were diverted to Muscat while PK-732 from Jeddah to Karachi was diverted to Lahore, PIA spokesman Danyal Gilani said in a statement.

"Due to heavy fog the visibility was less than 50 meters, hence the plane could not land in Karachi," he told Dawn.com separately.

He said the two flights were diverted to Muscat as visibility at all airports near Karachi was poor. Now with improved visibility flight operation at Karachi has been restored.

The flight map on the plane tracking site FlightRadar24 shows PK-307 coming from Lahore circled over Karachi and then proceeded to Muscat when it was rerouted.

After the fog cleared, the plane took off for Karachi from Muscat and landed at 12:07pm.

"Now with improved visibility flight operation at Karachi has been restored," the statement said.

The diversions come at a time when the airline is facing intense public and media scrutiny. Since the Dec 7 PIA plane crash near Havelian this month, several incidents of flight diversions and delays caused by technical issues have embroiled the airline.