The blackout affected all major cities in the country including its capital Islamabad, its major economic hub Karachi, and the second largest city, Lahore.
Power cuts are frequent in Pakistan, which has faced a chronic energy crisis for years and has a complex and dilapidated distribution system. Many of its approximately 210 million inhabitants go without power for long hours every day, and the phenomenon worsens during the heat of summer.
The outage is due to a malfunction that occurred at 11:41 pm local time on Saturday (1841 GMT) in the south of the country, Energy Minister Omar Ayub Khan said on Twitter, saying he was basing himself on the first available evidence.
“The malfunction affected the country’s transmission system (…) which led to the shutdown of power stations,” he explained, adding that power was “gradually being restored throughout the country”.
Teams worked through the night to restore power, which had partially returned in the morning to Islamabad and Lahore.
The national company managing the distribution of electricity (NTDC) said a committee would be formed to investigate the causes of the blackout.
It disrupted the electricity supply to all of the country’s hospitals, which had to rely on their generators.
Netblocks, a nongovernmental organization that records internet outages, said connectivity in Pakistan fell as a result of the outage, standing at “62% of regular level,” according to its Twitter account.
In 2015, 80% of Pakistani territory, including major cities, had already been plunged into darkness by a power cut caused, according to the government, by an attack by Baloch separatists on a power line in a remote district of the province of Balochistan (southwest).
The blackout, one of the worst in Pakistan’s history, even affected one of the country’s international airports.