India, Dec. 20 -- Dense fog converged with air pollution to smother Delhi for yet another day on Friday, disrupting over 700 flights and leading to the cancellation of at least 177 more, with worse weather expected over the weekend.

The India Meteorological Department (IMD) issued an orange alert for fog on Saturday and the Air Quality Early Warning System (AQEWS) predicted the air quality index - which barely budged from 373 to 374 in the 24 hours ended at Friday on 4pm - to climb into the 400+ "severe" category over the weekend.

"Dense to very dense fog is expected to form at several places across the city in the early hours of Saturday. At night, a shallow fog or mist might be observed," an IMD official said, adding that Sunday and M...