New Delhi, Dec 26 (IANS) Delhi saw a heavy fog cover Sunday morning that led to a sharp drop in visibility, disrupting several international and domestic flights at the airport here, officials said.

The thick fog saw the visibility dropping to near zero in the city, according to the India Meteorological Department (IMD). The general visibility at the main and new runways at the Indira Gandhi International (IGI) airport was less than 50 metres, leading to delays, diversions and cancellations of several flights, an airport official said.

About 15 domestic flights from Delhi were cancelled and 12 international, mostly scheduled to depart late Saturday and early Sunday, were rescheduled.

Seven international flights coming to the national capital were delayed by up to five hours, the authorities said.

"As the IMD has informed, the skies will be clear later during the day. Most of the morning flights are delayed by up to five hours or have been rescheduled," the airport official said.

The airlines also cancelled quite a few domestic flights, including those to Lucknow, Leh, Srinagar, Jaipur, Kullu, Amritsar, Mumbai, Patna, Chandigarh and Goa due to the fog.

On Saturday night, few international Air India flights to New York, Chicago and Toronto were delayed after visibility dropped.

The flights, which were scheduled to depart between 1.30 a.m. to 3.30 a.m., were rescheduled to 11.30 a.m.

Apart from flights, several trains were also delayed due to the dense fog.

Weather officials, however, said the skies would remain clear later during the day.

The minimum temperature Sunday was 7 degrees Celsius, one notch below the average for this time of the season. The maximum temperature will be around 20 degrees Celsius, the weather official said.

The coldest day of the season in Delhi so far was Dec 22 with a minimum temperature of 5.2 degrees.