New Delhi, Jan 16 (ANI): A dense fog enveloped national capital New Delhi and surrounding areas on Friday morning, disrupting flights, train services and road traffic. Visibility at the Indira Gandhi International Airport (IGI Airport) had reduced to zero meters reportedly, which delayed the arrival and departure of many international and domestic flights. Northern Railway authorities said over 50 Delhi-bound trains were running late, whereas 17 trains had been rescheduled. Five trains had been cancelled, it added. The Meteorological department, however, has predicted clear skies later in the day, and expects a maximum temperature to hover around 16 degree Celsius.