The UN Office for the Coordination of Humanitarian Affairs (OCHA) said Wednesday that Israeli strikes over the past 24 hours have hit sites hosting displaced Palestinians, with some of them injured and killed.

UNITED NATIONS, July 17 (Xinhua) -- UN Secretary-General Antonio Guterres strongly condemns the Israeli strike on the Holy Family Church in Gaza, a sanctuary for civilians, a UN spokeswoman said Thursday.

"Attacks on places of worship are unacceptable," said Stephanie Tremblay, associate spokesperson for the UN chief. "People seeking shelter must be respected and protected, not hit by strikes."

Too many lives have already been lost. The secretary-general calls on all parties to ensure that civilians are respected and protected at all times and allow humanitarian aid to flow into Gaza at scale, said Tremblay, adding that there is an urgent need for an immediate ceasefire and the immediate and unconditional release of all hostages.

The UN Office for the Coordination of Humanitarian Affairs (OCHA) said Wednesday that Israeli strikes over the past 24 hours have hit sites hosting displaced Palestinians, with some of them injured and killed.

Between July 8 and 15, according to OCHA, more than 11,600 people were newly displaced, bringing the overall displacement since the breakdown of the ceasefire on March 18 to more than 737,000 people, about 35 percent of Gaza's population. Since the outbreak of the war in Gaza 21 months ago, nearly everyone has been displaced, in many cases multiple times.

The office said that most housing in Gaza is flattened or otherwise uninhabitable, and many families stay out in the open. Meanwhile, many displaced people have been hesitant to bathe in the Mediterranean after Israeli authorities reinstated a ban on access to the sea along Gaza's coast, specifically prohibiting swimming and fishing.

For many, the sea has been their only option to wash, due to near-total collapse of water infrastructure, said OCHA.

Fuel shortages continue, said OCHA, while the amounts of fuel that Israel allows into Gaza are still nowhere near enough to keep life-saving services running.

"There was a small but important step forward today: For the first time in more than 135 days, we were finally allowed to bring in some benzene, which powers ambulances and other critical services," the humanitarians said. "That's in addition to the limited amounts of diesel allowed over the past week."

However, OCHA called for more fuel, including both benzene and diesel, to enter Gaza regularly, as well as an immediate lifting of the ban on shelter materials. "Lives depend on both (fuel and shelter)," the humanitarians said.