The blackout was reported on social media by residents of Karachi, Lahore, Islamabad, Multan, Kasur and others.
The power outage was reported shortly before midnight on Saturday almost simultaneously in many cities.
The reason for the breakdown was not immediately clear.
This is Not official but an expert opinion:
When a large plant trips, the voltage and frequency drops instantly. Plants that are on system, are designed to automatically open breakers and isolate themselves to avoid damage. Now they will have to bring them back one by one.
Islamabad Deputy Commissioner Hamza Shafqaat in a tweet said the blackout was caused by the National Transmission & Despatch Company (NTDC) system tripping.
“It will take sometime before everything gets back to normal,” he wrote.
Special assistant to the prime minister Shahbaz Gill said federal Energy Minister Omar Ayub and his entire team were working on the issue of the breakdown. He said citizens would be updated on the situation soon.