The United Nations is warning that Israel’s order for Palestinians to leave Gaza City will fuel mass suffering and is insisting that civilians must be protected and their needs must be met whether they flee or stay.

U.N. spokesman Stephane Dujarric told reporters Wednesday that this warning from the U.N. humanitarian office means that all parties involved in the conflict in Gaza must respect international humanitarian law at all times. Protection of civilians and the infrastructure for their survival are key requirements of the law.

The U.S. has agreed to send Israel hundreds of 500-pound bombs from a shipment that the Biden administration withheld because of concerns about Israeli operations in the southern Gaza city of Rafah, according to three U.S. officials.

U.S. President Joe Biden announced in May that he would not supply offensive weapons that Israel could use to launch an all-out assault on Rafah over concern for the well-being of hundreds of thousands civilians sheltering there.

A suspected attack by Yemen's Houthi rebels targeted a Liberian-flagged tanker in the narrow Bab el-Mandeb Strait on Wednesday, as authorities acknowledged the rebels launched their longest-range attack yet on a U.S.-flagged vessel near the Arabian Sea.

The attacks come after an unexplained pause of a week and a half. The rebels may be regrouping ahead of the arrival of a new U.S. aircraft carrier to the region after the USS Dwight D. Eisenhower began heading home.

France on Wednesday condemned Israel's recent deadly air strikes on schools sheltering displaced Palestinians in Gaza, declaring such tactics "unacceptable".

"We call for these strikes to be fully investigated," the foreign ministry said, highlighting a strike on Tuesday on a school near the southern city of Khan Yunis.

Syria's national airline resumed regular services to Saudi Arabia after a 12-year suspension on Wednesday as the first flight arrived in Riyadh.

The Israeli army on Wednesday dropped leaflets on Gaza City urging all residents to leave for safe zones amid an intensified military offensive on the Palestinian territory's main city.

The thousands of leaflets, addressed to "everyone in Gaza City", set out routes out of the city to the south and warned it would "remain a dangerous combat zone", an AFP journalist said.

An Israeli airstrike on a school-turned-shelter in southern Gaza killed at least 25 Palestinians on Tuesday, as heavy bombardment in the north forced the closure of medical facilities in Gaza City and sent thousands fleeing in search of increasingly elusive refuge.

Israel's new ground assault in Gaza's largest city is its latest effort to battle Hamas militants regrouping in areas the army previously said had been largely cleared.

The pier built by the U.S. military to bring humanitarian aid to Gaza will get reinstalled Wednesday to be used for several days, but then the plan is to pull it out permanently, several U.S. officials said. It would deal the final blow to a project long plagued by bad weather, security uncertainties and difficulties getting food into the hands of starving Palestinians.

Heavy Israeli bombardments pounded Gaza City on Tuesday, driving thousands of Palestinians to flee and forcing medical facilities to shut down because of the latest offensive in the territory’s north. And in southern Gaza, an apparent Israeli airstrike on a school-turned-shelter killed at least 25 people and wounded dozens more, Palestinian health officials said.

A war monitor said two people were killed Tuesday in an Israeli strike on a vehicle belonging to Lebanon's Hezbollah group in the Damascus countryside near the Lebanese border.

Hezbollah has traded almost daily cross-border fire from Lebanon with the Israeli army since October in support of Palestinian ally Hamas, with Israel targeting operatives from the group in both Lebanon and neighboring Syria.

Qatari and Egyptian mediators are cajoling Israel and Hamas towards negotiations on a plan to end their war, which has left tens of thousands dead.

U.S. President Joe Biden first outlined in late May what he called an Israeli initiative for a truce and hostage release deal. Mediators are now embroiled in secret contacts with both sides, who have launched diplomatic barbs ahead of this week's talks.