At least 52 trains were running late while 12 others were rescheduled on Friday due to heavy fog in many parts of north India, a railway official said.
According to the Northern Railway official, the Patna Rajdhani was running 25 hours late, the Brahmputra Mail was running 24 hours behind schedule and the Bhubaneswar Rajdhani Express was over 22 hours late.
The official also said that 12 trains were rescheduled.
Meanwhile, according to the Delhi International Airport Limited, which manages operations at the Indira Gandhi International Airport here, flight operations were not affected on Friday.