Fifteen Palestinians, including at least four members of Hamas, and three Israeli soldiers have been killed in separate clashes inside the Gaza Strip today.

According to Hamas, eight Palestinians were killed this afternoon when Israeli helicopters fired four missiles into central Gaza.

Different accounts by Palestinian witnesses said they heard separate explosions. The Israeli army confirms a helicopter fired at a group of armed Palestinians.

Earlier today, three Israeli soldiers and 4 Hamas gunmen were killed in clashes near Gaza's main fuel terminal.

Hamas said Israeli soldiers backed by helicopters killed four of their members during fighting east of Gaza city, a few hundred metres from the Nahal Oz border terminal used to supply fuel to the coastal territory.

An army spokeswoman, Major Avital Leibowich, said the soldiers were killed in a battle with Palestinian gunmen who were approaching the fuel terminal.

"Raiding our areas will never be a picnic," Abu Ubaida, a spokesman for Hamas's armed wing, told a news conference in Gaza.

Israel stopped fuel deliveries to Hamas-controlled Gaza last week after an attack on the fuel terminal killed two Israeli civilians.

Fuel supplies to Gaza's main power station did not resume today as expected. European and Palestinian officials said Israel had blamed the delay on the attack and other security concerns.

The fuel cuts have hampered travel for Gaza's 1.4m people. Four Gaza universities shut down on Monday because students could not get to class, officials said.

Hamas seized control of Gaza in June from forces loyal to the Palestinian president, Mahmoud Abbas.

Israel frequently attacks Gaza in response to militants launching rockets into southern Israeli towns.