On Friday morning Delhi witnessed Zero visibility at Indira Gandhi  International (IGI) airport. Flight operations  were severely hit  and atleast 150 flights arriving or departing from New Delhi was delayed by several hours. Between 6 a.m. and 9a.m. no take offs  could take place . As many  as 129 domestic flights and 39 international ones were delayed, many by three to five hours. Airport sources say that the delays in the morning hours will have a cascading effect on flights throughout the day, therefore, the number of flights affected will go up. From 10:45 a.m. and 12:15 a.m. there are restrictions on civilian flights due to rehearsals for Republic day on January 26.