The airline reported that an average of 17 per cent of PIA passengers who landed in Karachi in the last 15 days had tested positive for the novel coronavirus.
The airline has taken 2,348 passengers back to the town in its last 15 flights. Of these, 401 people tested the deadly virus for positive.
The passengers were transferred to quarantine centres. The largest number of positive tests resulted from a flight that arrived from Sharjah on April 29 in Karachi.
In that flight a total of 127 people had coronavirus. While, after testing negative, 1,714 passengers have been allowed to leave for their homes.
The passengers arrived from various parts of the world, according to the airline.
PIA has brought back Pakistanis stuck abroad through its special flights following an increase in coronavirus cases after the country shut down its international flight operations.