Gaza's sole power station was shut down on Saturday evening due to lack of fuel supplies, the third closure in the past month.
A Ma'an correspondent said parts the Gaza Strip were plunged into darkness, but limited power was available in some locations.
The new closure comes just days after the plant was reopened, and Hamas and Egyptian authorities said an agreement would end the power outages.
Gaza's energy authority said the station, which had been running just one of its four generators, was shut down after the fuel crisis had cotinued to get worse, and called on Egypt to provide sufficient fuel.
After fuel deliveries via underground tunnels from Egypt were shut off in recent weeks and the parties seek agreement on an "official" channel for supplies, 1.7 million residents of the coastal strip have faced up to 18-hour blackouts each day.
The new power outage comes as Gaza faces a series of deadly attacks by Israeli warplanes. The Gaza Strip has been pummeled by Israeli airstrikes since Friday, killing 15 Palestinians and wounding more than 25, while Gaza militants have barraged southern Israel, injuring four Israelis.