US President Joe Biden and Israeli Prime Minister Benjamin Netanyahu are set to speak on Thursday in their first phone call since an Israeli strike on a humanitarian convoy killed seven aid workers in Gaza.

Biden has led a chorus of international anger over the attack on employees of US-based World Central Kitchen, who were distributing desperately needed food to a population on the verge of famine.

"I can confirm President Biden and Prime Minister Netanyahu will speak tomorrow," a US official told AFP on Wednesday.

Nearly six months into the Gaza war, with the families of hostages still held captive by Hamas desperate for their release, many former hostages are finding the words to describe the ordeal of captivity.

"I went through hell," Aviva Siegel, who spent 51 days in captivity in Gaza, told AFP.

On the morning of October 7, Siegel, in her early sixties with round glasses and dark grey hair, was with her husband Keith when Hamas fighters burst into their home in Kfar Aza kibbutz, kidnapped them and took them to Gaza.

US President Joe Biden and Israeli Prime Minister Benjamin Netanyahu will speak on Thursday, a US official said, in their first call since an Israeli strike killed seven aid workers in Gaza.

The call comes after Biden expressed outrage over the deaths of the employees of the US-based World Central Kitchen group and said Israel must do more to protect aid workers and civilians.

"I can confirm President Biden and Prime Minister Netanyahu will speak tomorrow," a US official with knowledge of the matter told AFP on Wednesday.

A Palestinian-American doctor said he walked out of a Ramadan event with President Joe Biden at the White House to show solidarity with the people of Gaza against Israel's offensive.

Thaer Ahmad, who traveled to Gaza earlier this year, told CNN he left the meeting between Biden and members of the Muslim community on Tuesday in protest at US "rhetoric" supporting Israel.

Spanish Prime Minister Pedro Sanchez said Wednesday the response of his Israeli counterpart Benjamin Netanyahu to an air strike that killed seven aid workers was "insufficient" and "unacceptable".

"We are waiting for a much more detailed clarification of what the causes have been, bearing in mind that the Israeli government knew about the actions and the itinerary of this NGO on the ground in Gaza," Sanchez told a Doha news conference at the end of a three-nation tour of the Middle East.

An ongoing Lebanese army investigation has determined that a landmine wounded three UN military observers and a translator last week, a judicial official said Wednesday, as Israel implicated Hezbollah.

"Preliminary results of a Lebanese army investigation have found that the observers were wounded by a landmine," the Lebanese official told AFP, requesting anonymity as they were not authorised to speak to the media.

The bodies of six foreign aid workers killed in an Israeli strike were on Wednesday taken out of Gaza to Egypt for repatriation, a security source said, as Israel faced a chorus of outrage over their deaths.

The Israeli military killed seven staff of the US-based food charity World Central Kitchen on Monday in an attack that UN chief Antonio Guterres labelled "unconscionable" and "an inevitable result of the way the war is being conducted".

The Palestinians on Tuesday officially revived their bid for a full member state in the United Nations -- a process with an uncertain outcome but one they say is necessary in the face of Israel's offensive in Gaza.

The Palestinians, who have had observer status at the world body since 2012, have lobbied for years to gain full membership, which would amount to recognition of Palestinian statehood.

The families of Israeli hostages held in Gaza by Hamas on Tuesday blasted their country's leader as a "traitor" as anger at Prime Minister Benjamin Netanyahu's handling of the war grew in the fourth consecutive night of mass protests.

Thousands gathered in front of the country's parliament, with hostage families and former prime minister Ehud Barak blaming Netanyahu for the October 7 "disaster" and demanding an election.

US President Joe Biden has downsized the traditional Ramadan event at the White House amid tensions over his support for Israel's offensive in Gaza, officials said Tuesday.

Muslim leaders will meet Biden "to discuss issues of importance to the community", but asked for there to be no fast-breaking dinner, known as iftar, Press Secretary Karine Jean-Pierre said.

Instead, Biden and Vice President Kamala Harris will host a small prayer and iftar after the meeting with several senior Muslim administration officials, Jean-Pierre told a daily briefing.