LAHORE: Minimum visibility caused by dense fog has adversely affected flight operations at Lahore’s Allama Iqbal International Airport as several flights have been delayed. The visibility has dropped to 800 metres at the runway. Several in and outbound flights were postponed due to the fog. International flight QR-621 from Doha coming to Lahore has been delayed due to bad weather conditions at the airport. PK-789 coming from Toronto to Lahore, Istanbul-bound PIA’s flight PK-715 from Allama Iqbal airport were also delayed owing to foggy conditions. Ras Al-Khaimah-bound flight G9-853 from Lahore and G9-852 coming to Lahore from Ras Al-Khaimah are also facing delays. Furthermore, Qatar Airways flight QR-620 bound for Istanbul from Lahore has also been delayed. three Pakistan International Airlines (PIA) flights were also cancelled due to dense fog, he informed. Lahore is used to witness fog in early winter but for some years smog and pollution have adversely affected the region. Continued smog and air pollution restrict visibility range which also result in hygiene issues.