Saudi Arabia on Friday denounced the displacement of Palestinians from Gaza and attacks on "defenceless civilians", its strongest language criticising Israel since the war broke out.
Riyadh "affirms its categorical rejection of calls for the forced displacement of the Palestinian people from Gaza, and its condemnation of the continued targeting of defenceless civilians there," the foreign ministry said in a statement.
Thousands of Palestinians fled to southern Gaza in search of refuge on Friday after Israel called for over a million of them to evacuate the north of the blockaded enclave before an expected ground offensive.
It comes amid continued strikes on the strip in retaliation for a surprise weekend attack by Hamas, the deadliest in Israel's history.
The Saudi statement was published as US Secretary of State Antony Blinken arrived in Riyadh as part of a six-nation tour of Arab countries.
US officials have appeared to backtrack on earlier efforts to let Gazans flee to neighbouring Egypt, saying they did not see wide support, and have instead promoted the idea of "safe areas" within Gaza.
The war has dealt a blow to attempts by the administration of US President Joe Biden to facilitate normalisation between Israel and Saudi Arabia, home of the two holiest sites in Islam.
Saudi Arabia, which has never recognised Israel, has issued several statements in the past week affirming its support for the Palestinian cause.
On Thursday, Saudi state media reported that de facto ruler Crown Prince Mohammed bin Salman discussed "the current military situation in Gaza and its environs" with Iranian President Ebrahim Raisi. It was the first call between the two leaders since their countries announced a surprise China-brokered rapprochement in March after seven years of severed ties.
Friday's foreign ministry statement also included a call for the international community "to quickly move to stop all forms of military escalation against civilians, prevent a humanitarian catastrophe, and provide the necessary relief and medical needs for the residents of Gaza."
"Depriving them of these basic requirements for a decent life is a violation of international humanitarian law and will exacerbate the depth of the crisis and suffering that this region is witnessing," it added.
At the Grand Mosque in Mecca on Friday, the imam, Sheikh Osama bin Abdullah Khayyat, teared up while leading prayers, saying: "May God protect the Muslims in Palestine."
Protesters in New York call for a 'free Palestine'
Cries of "Free Palestine" rang out in New York on Friday, as thousands of protesters took to the streets to denounce Israeli bombings in the Gaza Strip.
Calling for an end to "Israeli occupation" and the "liberation" of the Palestinian territories, protesters took up multiple blocks in a city that serves as a crossroads for religions and nationalities spanning the world.
The largely youthful protest -- which drew demonstrators of all origins, some sporting Palestinian flags and keffiyehs -- accused Israel of "genocide" and called for the US to withdraw support for its Middle Eastern ally.
Hamas fighters from Gaza burst through the heavily militarized border into Israel on Saturday, killing more than 1,300 people -- mostly civilians -- in an attack compared to 9/11 in the United States.
Israel has responded with a fierce bombardment of missile strikes on the densely populated enclave, killing at least 1,900 Gazans -- again mostly civilians, including more than 600 children.
Thousands are attempting to flee to southern Gaza after Israel warned them to evacuate before an expected ground offensive.
"I'm extremely worried, this has to stop," said Liz Zacharia, a professor attending the march.
"The settler colonial project of Israel has to end now," said Zacharia, whose father was from Jerusalem, adding that it feeds a growing "cycle of violence" and "oppression of Palestinians."
"From the river to the sea, Palestine will be free," protesters chanted, a slogan some Jewish organizations say calls for the destruction of Israel and is anti-Semitic.
Supporters of the slogan say it calls for equality for Palestinians and Israelis.
About 200 pro-Palestinian demonstrators also gathered in the southern US city of Miami.
A heavy police presence guarded the protest and made sure to keep a distance between it and the dozen pro-Israel demonstrators across the street.
Anas Amireh, 51, a businessman and the son of Palestinian immigrants, said that responding to the killings of innocents in Israel with "another genocide... in the Gaza Strip is a criminal war and it is wrong."
"I feel it's my duty, not just as a Muslim, but also as a human being, to see everyone show up because of the crimes that the Israel occupation has caused upon the Palestinian people," said Laibah Faiaz, a 21-year-old New York protester.
"No one is acknowledging the scale of destruction that they've unleashed upon these innocent people," she added.
New York, home to the largest Jewish population outside of Israel, has been the scene of a series of demonstrations in support of the Palestinian cause as well as vigils and demonstrations in solidarity with the Israeli victims of Hamas attacks.
Protests have popped up on college campuses across the US as well.