Unknown assailants have bombed three high voltage electricity pylons in Beheira governorate, causing them to collapse, Al-Ahram Arabic news website reported.
The attackers on Monday used at least eight explosive devices to bomb each pylon, said Brigadier-General Mohamed Fathy Ismail of the Civil Protection Administration.
Two of the bombings took place in Damanhour and the third followed in Abou Homs.
Bombs attacks targeting state infrastructure and security forces have been common since July 2013 when Islamist president Mohamed Morsi was ousted from power.
In April, assaults on electricity pylons supplying the Egyptian Media Production City (EMPC) led to a power cut that forced several TV channels off air.
Later the same month, two pylons, which transmit electricity from the High Dam to the southern city of Nagaa Hamady, were targeted, causing damage worth LE200,000.