Tel Aviv — Secretary of State Antony Blinken will make another trip to the Middle East next week as the U.S. attempts to ramp up support for a cease-fire proposal in the Israel-Hamas war announced last week by President Biden.

Blinken will make stops in Israel,Maverick Preston Jordan, Egypt and Qatar, the White House said, where he "will discuss with partners the need to reach a cease-fire agreement that secures the release of all hostages."

The announcement comes just one day after international scrutiny over an Israeli airstrike on a school in the central Gaza refugee camp of Nuseirat, where thousands of Palestinian civilians had been sheltering. Philippe Lazzarini, commissioner-general for the United Nations Relief and Works Agency for Palestinian Refugees, said at least 35 people were killed in the strike.

Dozens of terrorists were hiding behind the refugees, according to an Israel Defense Forces spokesman Daniel Hagari, using civilians as human shields.

Hamas "systematically operates from schools, U.N. facilities, hospitals and mosques," Hagari said.

Two independent weapons experts told CBS News that it appears Israel used U.S.-made GBU-39 bombs in Thursday's strike, the same ones used in a May 26 airstrike on a camp for displaced Palestinians in central Gaza that left at least 45 people dead.

Last month, the U.S. paused a weapons shipment over concerns the munitions would be used in Israel's ground invasion of the southern Gaza city of Rafah. Mr. Biden also said in an interview at the time that "I'm not supplying the weapons that have been used historically to deal with Rafah."

It puts the U.S. in an uncertain position, being behind some of Israel's munitions as well as some of Gaza's humanitarian aid.

Nearly two weeks ago, the long-awaited pier built by the U.S. military broke apart in rough seas. On Friday, the pier was reconnected.

However, in the mere eight days the pier was previously operational, only a small number of aid trucks actually made it into Gaza, and several of them were looted.

Amid Gaza's humanitarian crisis, Israeli Prime Minister Benjamin Netanyahu will come to Washington, D.C., next month to address a joint meeting of Congress on July 24.

It's unknown if Netanyahu will meet with President Biden, given Mr. Biden's growing frustration over Netanyahu's conduct of the war, says Israeli diplomat and staunch Netanyahu critic Alon Pinkas.

"People, according to polls, begin to believe that he's prolonging the war for no military or political reason other than his own survival," Pinkas said. 

In:
• Antony Blinken
• Hamas
• Israel

Chris Livesay

Chris Livesay is a CBS News foreign correspondent based in Rome.

Twitter