High tension power pylons supporting power transmission lines in Jamshoro were damaged when bombs planted at their base exploded on Wednesday.
Due to the attack, power supply to Hyderabad city was partially disrupted.
Police said that after the incident was reported, squads were rushed to the spot, while the Bomb Disposal Squad was also requested.
Officials, however, said that they have yet to trace the culprit behind the incident.
Police further said that last night, unidentified people had attempted to disrupt the power transmission system using explosives but failed.
No one has thus far claimed responsibility for the attack.
Meanwhile, when asked, a representative of K-Electric said that there has been no impact on its operations since the power transmission grid in Jamshoro is not directly linked to it.