U.N. chief Antonio Guterres called for the blockade of Gaza to be lifted Wednesday as he visited the Palestinian enclave enduring "one of the most dramatic humanitarian crises" he had seen.

Once a day, the electricity comes on and the Ahmed household whirs into action -- even if it's the middle of the night.

The Gaza Strip may already be "unlivable," a United Nations official warned Tuesday, after a decade of Hamas rule and a crippling Israeli blockade.

Robert Piper, the U.N.'s top humanitarian official in the Palestinian territories, told AFP in an interview to mark a new report on living conditions in Gaza all the "indicators are going in the wrong direction."

Following are key dates in the evolution of Islamist Palestinian movement Hamas, a sworn enemy of Israel that seized power in Gaza 10 years ago.

Israel will reduce electricity supplies to the Gaza Strip after funding cuts by Palestinian President Mahmoud Abbas, a minister said Monday, worsening an already severe shortage in the Hamas-run enclave.

Gulf sanctions against Qatar could damage reconstruction in the Hamas-run Gaza Strip, where it has provided large financial backing, the head of a major humanitarian charity warned Tuesday.

An Israeli tank opened fire Thursday on a Hamas position in Gaza, in response to shots coming from the Palestinian territory, the Israeli army said.

The Gaza Strip's only functioning power plant was out of action Sunday after running out of fuel, the head of the territory's electricity provider told AFP.

Israel's army targeted Hamas posts in the Gaza Strip with tank fire early Tuesday after gunfire against its forces, the second such incident in recent days, officials said.

Gaza's largest desalination plant will be operational in the autumn as the Palestinian enclave tries to avert a potential humanitarian crisis over a lack of drinkable water, officials said Tuesday.