Heavy fog across north India on Saturday threw train traffic out of gear with 100 trains running late and five of them being rescheduled.
Northern Railway officials said train traffic has been disrupted following dense fog in many areas of Punjab, Haryana and Uttar Pradesh.
The Lucknow Shatabdi has been cancelled from both sides while five trains have been rescheduled, including the North East Express and Puri Express.
At least 100 trains are running late.
All trains are running at a snail's pace and a speed restriction on running of trains has come into force in some sections between Delhi and Kanpur, they said.