Unknown assailants have blown up an electricity pylon in Qalioubiya governorate, north of Cairo.
The attack, late on Saturday, is the latest in a series of similar incidents, an electricity ministry spokesman told Ahram Online.
The explosion damaged the trestles of the 500kv tower, causing it to collapse, spokesperson Mohamed Yamany said, without elaborating on how the incident took place.
The attack, which took place during the night rush time, has had effects further afield. It caused cuts to two circuits at a station in the northern Mediterranean town of Abu Kir with a capacity of 1300 megawatt, Yamany added, saying the units had been repaired shortly after.
Repairs should take between four to six weeks and cost LE3 million (around $420,000), with necessary diversions being carried out to prevent power shortages in affected areas.
The explosion is the seventh in two weeks, according to Ahmed Hanafy, head of the Egyptian Electricity Transmission Company.
Egypt's electricity grid has come under frequent attack by unknown assailants targeting electricity substations, towers and circuits in several parts of the country.
On Wednesday, assailants blew up a pylon feeding West Cairo and a district north of the capital.
Egypt has already been plagued by recurrent summer blackouts due to a severe energy crunch.
Bombings and shootings by militant Islamists, mainly targeting army and police personnel, have been commonplace since the military ouster of president Mohamed Morsi, an Islamist, last summer