At least 69 trains were running late while four were cancelled on Saturday due to heavy fog in many parts of north India, a railway official said.
According to the Northern Railway official, the Brahmputra Mail and Vikramshila Express were running 26 hours late while Nandan Kanan Express was running 16 hours behind schedule.
The official added that the Udyan Abha Toofan Express, Sampoorna Kranti Express from New Delhi to Rajendra Nagar, Taj Express and Kalka Mail were cancelled.
The official also said that 16 trains were rescheduled.
Meanwhile, according to the Delhi International Airport Limited, which manages operations at the Indira Gandhi International Airport in the capital, flight operations were not affected on Friday.