Gaza's only power plant has run out of fuel, forcing it to shut down after Israel cut off supplies, the Energy Ministry said on Wednesday.
That will leave only generators to power the territory.
Gaza Strip has been under intense bombardment by Israel after the Palestinian militant group Hamas launched a surprise attack on Saturday.
The blackouts come as Israel has decided to block fuel shipments into the Gaza Strip as part of what the Israeli government has called a “complete siege” on the territory run by the Hamas militant group.