Karachi, Jan 25 - Attempts to restore power are underway after a major blackout hit Pakistan around midnight on Saturday, leaving about 80 percent of the country shrouded in darkness, a report said.

Almost all of Pakistan including, Punjab, Khyber-Pakhtunkhwa, Islamabad and Balochistan plunged into darkness around 11:50 p.m. on Saturday night as Baloch separatists attacked transmission lines near Naseerabad in Balochistan, causing the national power grid to trip and shutting down electricity supply to most parts of the country, reported the Dawn.

Sharbat Umrani, the head of the local police station confirmed that the separatists blew up the transmission tower near Notal, a town in Naseerabad district in Balochistan.

Water and Power Secretary Younus Dagha said that the damage to the 220 kilovolt-Amperes (kVA) transmission lines between Sibi and Quetta led to a backward surge of power to the Guddu power plant in Sindh, which in turn caused a cascading effect on the entire national grid.

Taking notice of the "worst-ever" national power grid breakdown, Prime Minister Nawaz Sharif asked authorities to resume power supply on an emergency basis.

A K-Electric spokesperson said that the power supply had been partially restored in Karachi and other areas too will receive an electricity supply soon.

The attack near Notal was the third attack on the country's power grid in two weeks in Naseerabad. (ANI)