At least 21 trains were running late and seven cancelled due to dense fog in parts of north India on Tuesday morning, a railway official said.
The status of the delayed and cancelled trains was last updated till morning 5 a. m.
According to the Northern Railway official, nine trains were rescheduled.
The cancelled trains included New Delhi - Hyderabad Telangana Express, Jammu Tawi - Bhagalpur Amarnath Express, Jaynagar - Amritsar Saryuyamuna Express, New Delhi - Rajgir Shramjivi Express, Kota - Patna Express, New Delhi - Bhubhneswar Rajdhani Express and Amritsar - Kanpur Central Express.