Lebanon's state electricity company said on Saturday that its power plants had stopped working after protesters stormed a key substation and tampered with electrical equipment.
The nation is already grappling with power cuts that last at least 20 hours a day, owing largely to a financial crisis that has hampered key imports, including fuel for power stations.
Demonstrators angered by the power shortages stormed an Electricite du Liban substation in the Aramoun region north of Beirut on Saturday, the utility said.
“Protesters disconnected a 150-220 kilovolt power transformer and opened circuit breakers connecting the Zahrani power plant to the Aramoun station,” it said.
“This caused disturbances on the electrical grid, which led to a total blackout across Lebanese territory as of 17:27 (1527 GMT)".
The disruption will pile more pressure on operators of private generators, which are already struggling to keep up with the near-total absence of state-produced power.
Private generator owners have increased prices and rationed supply in recent months, with costs surging after the government gradually lifted fuel subsidies.
The average generator bill for a Lebanese family usually adds up to more than the monthly minimum wage of 675,000 Lebanese pounds — now worth just $22 as the local currency hits record lows against the dollar on the black market.
The international community has long demanded a complete overhaul of Lebanon's electricity sector, which has cost the government more than $40 billion since the end of the 1975-1990 civil war.
Lebanon has reached an agreement on bringing Jordanian electricity and Egyptian gas into the country via war-torn Syria, while Shiite movement Hezbollah has separately been sourcing oil deliveries from Iran.