ISLAMABAD: Special Assistant to the Prime Minister for Political Communication Shahbaz Gill on Monday said investigation into the interruption in power supply was underway to ascertain reasons and to avoid such incidents in the future.

However, he said, talking to a local news channel, the transmission lines were not up-graded in previous regimes and it was the main cause of power breakdown across the country.

The SAPM said Federal Minister for Energy Omar Ayub Khan himself has been analyzing and monitoring the matter of interruption of electricity supply.    

A day ago, massive power breakdown had plunged the country into darkness. According to the initial technical report, a fault had developed in Guddu Power House after which frequency in the national grid instantly fell from 50 to zero.