Head of Hamas political bureau said it will not back down from wanting to end the blockade on the Gaza Strip.

The Israeli army says its tanks have hit Hamas targets in the Gaza Strip on Sunday after Palestinian balloon attacks across the border continued.

An early-morning military statement said there had been airborne explosive and incendiary attacks into southern Israel on Saturday.

There were no immediate reports of casualties from any of the incidents.

Palestinian sources said an Israeli artillery shell was fired towards a field control point east of Khan Younis, and another shell east of Deir al-Balah in the central Gaza Strip.

According to the Israeli fire brigade, the fire bombs - crude devices fitted to balloons, inflated condoms or plastic bags inflated with helium - have triggered more than 400 blazes in southern Israel.

The Israeli army has carried out attacks on Gaza almost daily since August 6, along with further tightening a devastating blockade it has imposed on the Palestinian territory since 2007.

Under the new measures, it banned the entry of fuel for Gaza's sole power plant, plunging it into darkness.  

The Gaza Strip has a population of two million people, more than half of whom live in poverty, according to the World Bank.

The head of the Hamas political bureau, Ismail Haniya, said his movement - which controls the Gaza Strip - would not back down from wanting to end the Israeli blockade.

"Our decision and the decision of our people is to go ahead with ending this unjust siege in all its forms," Haniya said in a statement issued by his office early on Sunday.

"The leadership of the movement is closely following the current situation in the Gaza Strip in terms of communications and mediation carried out by many parties to work to break and end the siege on the strip."

An Egyptian delegation has been shuttling between the two sides to try to broker a renewal of an informal truce under which Israel committed to easing its 13-year blockade of Gaza in return for calm on the frontier between the two.

It was joined this week by Qatar's Gaza envoy Mohammed al-Emadi who delivered the latest tranche of $30m in aid to the territory on Tuesday before holding talks with Israeli officials in Tel Aviv.

Sources close to the Qatari delegation said Israeli officials had told al-Emadi they were willing to end a punitive ban on fuel deliveries for Gaza's power plant and ease their blockade if there was an end to the incendiary balloons.

Financial aid for the impoverished territory from gas-rich Qatar had been a significant component of the truce, first agreed in November 2018 and renewed several times since.

Under those terms, Israel had said it would take other measures to alleviate unemployment of more than 50 percent in the territory of some two million people. Those have yet to materialise.