Road and rail services were also affected.
At least two persons were injured on Wednesday morning near Sonipat town, 50 km from Delhi, in a pile up of cars on a busy National Highway (NH-1), police said.
Dense fog was reported from several areas of the NH-1 between Ambala and Kundli border of Haryana and Delhi.
A few trains were running behind schedule due to the fog.
In Punjab, fog was reported from some parts.
Met officials here said that the foggy weather will prevail over the next few days.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)