New Delhi, Dec 17 (IANS): Dense fog Tuesday enveloped the national capital, delaying flights and trains.

"Trains arrival and departures were delayed as visibility was poor...," A.S. Negi, a Northern Railway spokesperson told IANS.

Many trains have been rescheduled and the passengers have been informed via a sms.

"Passengers can contact (Delhi telephone number) 23747110, the new helpline number started by the Northern Railway," he said.

Kapil Sabarwal, spokesperson of Indira Gandhi International Airport, said: "Many international and domestic flight landings were delayed Tuesday morning because of the dense fog that created a major visibility problem."

The Met Office has forecast fog for the entire week.

The minimum temperature Tuesday was recorded one notch above the season's average at nine degrees Celsius, an official of the India Meteorological Department (IMD) said.

Though entire Delhi was wrapped up Tuesday in dense fog that is expected to last till the afternoon, the Met Office said that the day will become clear towards evening.

The maximum temperature is expected to hover around 24 degrees Celsius, while the maximum humidity at 8.30 a.m. was 100 percent.

Monday's maximum temperature was 24 degrees Celsius, while the minimum was nine degrees celsius.