He also said the departures of aircraft were suspended from 7.30 a.m to 9.30 a.m.
According to the weather office, visibility in Palam area on Thursday morning dipped to 50 metres and in Safdarjung area to about 350 meters.
Aircraft requires a minimum visibility of 120 metres for taking off.
Following the low visibility and delays in the takeoffs of the flights from the IGI airport, BJP National General Secretary Ram Madhav, who was also stuck in the aircraft, vented out his helplessness saying no technology can conquer nature.
"CAT III etc. notwithstanding, stuck in the aircraft for last three hours at Delhi airport with absolutely no information. ATC too unable to tell when the flight well get clearance. Fog in Delhi can cripple air movement at 12 noon. No technology can conquer nature," Madhav tweeted.
Currently, three runways at the airport -- 28, 29 and 11 -- are certified for 'CAT III B' operations, which would allow landing of the compliant aircraft with visibility as low as 50 meters.
"At least 12 trains have been delayed due to fog conditions," a Northern Railway official said.
He said Ahmedabad-New Delhi Rajdhani Express, Sealdah-New Delhi Duranto Express, Swatantra Senani Express were delayed by over 2.5 hours, while Bhubaneswar-New Delhi Duranto Express was running late by over three hours.
According to an NR official, Puri-New Delhi Purushottam Express and Brahmaputra Mail were running behind schedule by six hours. "Gaya-New Delhi Mahabodhi Express and Howrah-New Delhi Poorva Express have been delayed by 4.5 hours," he said.
Delhi witnessed a cold Thursday morning with the minimum temperature recorded at 6.7 degrees Celsius, one notch below the season's average.
The maximum temperature is expected to hover around 23 degrees Celsius. The humidity at 8.30 a.m was 100 per cent.
The pollution level remained "severe" for the second consecutive day, with the air quality index at 492, according to the System of Air Quality and Weather Forecasting And Research (SAFAR).
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)