At least 24 trains were delayed and one cancelled on Monday due to dense fog in most parts of north India, a railway official said.
According to the Northern Railway official, the Jogbani - Anand Vihar Express was running over 13 hours behind schedule, the Swatantrata Senani Express was 15 hours late and the Shaheed Express was over 11 hours late.
The official also said that at least five trains were rescheduled.
Meanwhile, according to the Delhi International Airport Limited, which manages operations at the Indira Gandhi International airport here, no flight was cancelled on Monday.