Flight operations at IGI airport here on Saturday resumed after eight hours of delay due to dense fog and a cable fault in the sophisticated electronic landing system which aids take off and landing in foggy conditions.

The flights started taking off and landing from around 1030 hours. Four morning flights were cancelled and at least 13 international ones, scheduled to land in the wee hours, were diverted to various places including Jaipur, Mumbai and Ahmedabad, airport sources said.

No flights could take off or land since 0200 hours when runway visibility dropped to 100 metres and general visibility to less 50 metres. Nineteen domestic flights in the morning were rescheduled.

A glitch in the cables connected to the instrument landing system (ILS) that measures and provides realtime runway visibility data to the Air Traffic Control (ATC) tower, forced the ATC officials to suspend flight operations.

Though Delhi has two runways equipped with Category-III B ILS that allows flight operations when the runway visibility is less than 100 metres, none could be used as the instrument located on Dwarka side could not provide the information to the ATC due to the fault, the sources said.

Jet Airways flight to Amritsar, JetLite flight to Ahmedabad, SpiceJet flight to Srinagar and Kingfisher flight to Dehradun were cancelled.

Visibility started to drop from 1.45 am and remained around 150 metres till 10 am, according to airport MeT department.