Dense fogDense fog engulfed motorways and the National Highway in various parts of Punjab and Sindh causing poor visibility on Sunday. However, Motorway section M-1 from Burhan to Swabi has been opened for vehicular traffic due to improved visibility. Motorway section M-2 from Lahore to Kot Momin has also been opened after improvement in visibility range. Motorway section M-3 from Faizpur to Abdul Hakeem was closed for traffic due to poor visibility caused by dense fog, a spokesperson of the Motorway Police said. Motorway section M-4 from Pindi Bhattian to Multan was also closed for vehicles for the same reason, the Motorway Police said. Motorway section M-5 from Multan to Sukkur was also closed for vehicular traffic in the morning. Swat Motorway was closed from Colonel Sher Khan Interchange to Chakdara and the motorway section from Multan to Khaniwal was closed for vehicles as fog blanketed the road, the Motorway Police said. Fog also covered the National Highway at Lahore, Chauhang, Mohlanwal, Manga Mandi, Phool Nagar, Jimbir, Pattoki, Okara, Habibabad, Renala Khurd, Sahiwal, Harappa, Cheechawatani, Kasuwal, Iqbal Nagar, Mian Channu, Khaniwal and Multan, according to the road police.