The Northern grid, supplying electricity to the region, tripped due to heavy fog and cold waves prevailing in the region causing blackout in many parts of Punjab, Haryana, Himachal Pradesh, Jammu and Kashmir and even Chandigarh on early Saturday.

Punjab State Electricity Board (PSEB) Chairman HS Brar said, "The snag developed due to thick fog over Punjab and Haryana. Our engineers are working to revive power supply. In some areas, power supply has been partially revived."

The tripping resulted in the unavailability of power that adversely hit rail services in Punjab and Haryana, making people to wait for hours amid bone-chilling cold waves prevailing in the regions. However, the concerned department became active very soon to resume power supply in few hours.

Ambala division railway manager, HK Haggi told reporters, "It was a difficult situation for both the passengers and the railway authorities. The trains were stranded for nearly three-and-a-half hours due to power failure."

The blackout delayed as many as 15 trains by one hour to three hours 30 minutes in Ambala division and a total of 50 trains in Ambala, Ferozepur and Delhi divisions, making railways authorities to use diesel engines to resume railway services.