Gaza's electricity company says two Israeli tank shells have hit a fuel tank of the Gaza Strip's only power plant, forcing it to shut down.
Even before the strike, residents had electricity for about three hours a day.
The strike came as Israeli aircraft and tanks struck symbols of Hamas control in Gaza in one the heaviest bombardment in three weeks of fighting.
A Palestinian health official puts the Gaza death toll at over 11-hundred. Israel has lost 53 soldiers, two civilians and a Thai national.
Iran's supreme leader on Tuesday called on Muslims from around the world to help arm Gaza Palestinians in their fight against Israel. The call by Ayatollah Ali Khamenei was his latest such message during the ongoing war between Gaza's Hamas rulers and Israel.
Khamenei claims that while Israel and America seek to disarm Hamas, Iran says ``the opposite ... the Muslim World has a duty to arm the Palestinian nation by all means.''
Iran, a staunch Hamas ally, does not recognize Israel and supports militant anti-Israeli groups such as the Palestinian Hamas and Lebanon's Shiite Hezbollah group.
Iran does not recognize Israel and has considered the Jewish state its archenemy since the 1979 Islamic Revolution that toppled the Western-backed monarchy and brought clerics to power.
Khamenei spoke at a prayer ceremony in Tehran as Shiite Iranians marked the beginning of Eid al-Fitr holiday that follows the Muslim fasting month of Ramadan.