The only power plant in the Hamas-run Gaza Strip was at a standstill on Tuesday due to an ongoing shortage of fuel caused largely by a dispute over taxes, officials said.
The plant has been closed since Saturday night when it ran out of fuel, said Ahmed Abu Al-Amreen, an official in the energy ministry.
Parts of the strip have been without power for 20 hours a day, the United Nations said, up from 12 hours previously.
The Palestinian Authority in Ramallah has gradually removed a tax exemption on fuel since January, demanding Hamas pay taxes on imports to besieged Gaza.
The cash-stripped Gaza energy authorities estimate the tax costs around 10 million shekels ($2.6 million) monthly and say they cannot afford it.
Relations between Islamist movement Hamas and the PA, which is dominated by bitter rivals Fatah, are fraught.
The rest of Gaza's energy needs are imported from Israel and Egypt.
The power station was closed down in July 2015 in similar circumstances.
It was damaged by shelling more than once during the 2014 war between Israel and Palestinian terrorists in Gaza.
AFP contributed to this report.