The United Nations is set to halt delivery of humanitarian aid to the Gaza Strip on Monday because its vehicles have run out of fuel, a UN official said.

Gaza has been facing a fuel shortage because of Israeli restrictions on supplies and a strike by Palestinian fuel distributors.

The UN Relief and Works Agency (UNRWA), which provides aid to Gazans, said the lack of fuel would force its food distribution programs to be halted on Monday, affecting some 650,000 people.

"The lack of petrol for our cars and other vehicles means that our education, relief and social service programs will be severely hit," said UNRWA spokesman Christopher Gunness.

The agency made a similar announcement last week but obtained a late delivery of some fuel.

An Israeli official said some diesel fuel intended for Gaza's power station had passed through on Sunday, but the transfer was halted when militants attacked the Nahal Oz fuel depot on the Israeli side of the Gaza border with mortar bombs.

The official added that as well as diesel for electricity and cooking gas, Israel was prepared to transfer petrol and diesel for vehicles but he said Gazans were not able to take delivery.

The Gaza fuel association said it went on strike to protest over Israel's supply limits which were cut back sharply after Palestinian militants attacked the Nahal Oz depot last month killing two Israeli civilians.