Humanitarian aid agencies poured resources into the Hamas-ruled Gaza Strip on Tuesday, providing basic essentials to thousands of Palestinians in need of emergency aid after Israel's 22-day offensive in Gaza.

Israel, which controls border entry points into Gaza, said it hoped to triple the number of trucks being allowed to deliver assistance to the coastal territory.

"We want to reach 500 trucks a day," said Isaac Herzog, the Israeli cabinet minister overseeing shipments from the Israeli side of the frontier. Around 150 trucks are currently delivering aid, including food and medicine, to the 1.5 million population.

The United Nations Relief and Works Agency, which has been operating in the Gaza Strip since 1948, said it carried out a preliminary assessment of the needs on the ground and determined that at least 330 million euros of emergency spending was required.

the figure is in addition to the 1.6 billion euros that Western diplomats have estimated will be needed to rebuild essential infrastructure such as roads, bridges, sewerage systems and some of the 22,000 buildings which Hamas said have been damaged.

"That 330 million euros is mainly for repair and rehabilitation of shelters and to a lesser degree UNRWA installations, 53 of which were either damaged or totally destroyed," said UNRWA spokesman Christopher Gunness.

"As the full scale of the destruction becomes clear, the figure will undoubtedly get larger. That is not a figure for reconstruction in Gaza, that is just for immediate repair and emergency relief," he said.

No home to return to

Aid workers said some 5,000 to 6,000 of those displaced in the past three weeks of fighting attempted to return to their homes following the separate cease-fires by Israel and Hamas on Sunday, only to find them destroyed or too damaged to live in.

The International Committee of the Red Cross, which provided medical and other assistance in Gaza during the conflict, said its post-conflict focus would be helping around 8,000 families - about 60,000 people - who it said had lost their homes or found the dwelling to be unliveable.

"The immediate need is mattresses, blankets, kitchen sets and plastic sheeting," said spokeswoman Anne Sophie Bonefeld. "We continue to supply hospitals with medicines and other supplies, including fuel for their generators.

"Our teams are also helping local technicians repair power lines, the Gaza waste treatment plan and looking into the problems of water supply in various communities," she said.

The initial emergency aid period is expected to last about 10 days, during which an assessment of longer-term needs would also be made, she said.

Dealing with the large number of amputees among the 5,300 injured is also a major priority. The World Food Programme, which provides emergency food assistance to Gaza's non-refugee population, estimated up to 365,000 Gazans are now in need of its help, up from 265,000 before.

The group has 4,400 tonnes of food already in Gaza - including wheat flour, cooking oil, chickpeas and sugar - which is being distributed throughout the territory.

"We are continuing with distributions and getting what we need across the border into Gaza," said spokesman Robin Lodge. "Next week we'll make a more detailed food security assessment, but at the moment we are making emergency deliveries, including to some of the 40,000 seeking shelter in U.N. compounds."

He said Israel was cooperating with allowing food to flow into Gaza, and aid groups were coordinating their work. "Everything has been going very smoothly so far," he said.