A power outage across Pakistan occurred Monday after a power surge on the national grid, the energy ministry said.

According to initial reports, the system frequency of the National Grid dropped at 7:34 this morning, causing a widespread power outage, the ministry said on Twitter.

Power has been restored at several grid stations of the Islamabad Electric Supply Company and the Peshawar Electric Supply Company, and authorities are working to restore the grid stations.

Energy Minister Khurram Dastgir told Geo TV that power units are temporarily shut down at night during the winter to save fuel costs.

"When the systems were turned on at 7:30 this morning one by one, a frequency change was registered in the southern part of the country between Jamshoro and Dadu. There was a voltage fluctuation and the systems were shut down one by one. This is not a serious crisis," Dastgir said.