Pakistan's government vowed to investigate if "foreign forces" were behind yesterday's power blackout on Tuesday.
Power Minister Khurram Dastgir Khan said that authorities suspected "foreign intervention such as hacking of systems."
"But its chances are very less. There have been incidents previously and we have to rule out this," he added.
Earlier, the minister stated that power was back at all the grid stations in Pakistan.
Meanwhile, Pakistan Prime Minister Shehbaz Sharif has apologized to the people for the widespread power outages.
"On behalf of my government, I would like to express my sincere regrets for the inconvenience our citizens suffered due to [the] power outage yesterday," Sharif wrote on Twitter. "On my orders an inquiry is underway to determine [the] reasons of the power failure. Responsibility will be fixed."
Pakistan woke up to power outages across the country on Monday, with the southern part of the nation comprising large cities Karachi and Lahore facing the brunt of the crisis.
In a statement on Twitter, the Energy Ministry said that the system frequency of the national grid went down at 7:34 am on Monday.