Palestinians in Rafah told AFP Saturday they were living in "constant terror" as Israel vows to push ahead with its planned assault on the south Gaza city flooded with displaced civilians.

Most of Gaza's population is sheltering in Rafah at the very south of the territory after fleeing Israeli bombardment elsewhere.

The Israeli army insists it will carry out a ground assault to eliminate Hamas militants, despite an international outcry and concern for the roughly 1.5 million Palestinians sheltering in Rafah, many in tents.

Hamas's armed wing released video Saturday of two men held hostage in Gaza who are seen alive and urging Israeli authorities to strike a deal for the release of all the remaining captives.

Campaign group the Hostages and Missing Families Forum identified the two as Keith Siegel and Omri Miran who were abducted by militants during the Hamas attack on southern Israel on October 7. Siegel also has US citizenship.

Police detained nearly 200 people at three US universities on Saturday as they cleared pro-Palestinian encampments, in the latest campus clashes triggered by protests over Israel's war against Hamas.

On the East Coast, police in Boston detained about 100 people while clearing a protest camp at Northeastern University, with social media posts showing security forces in riot gear and officers loading tents onto the back of a truck.

Iraqi religious leader Moqtada Sadr on Saturday expressed his support for pro-Palestinian encampments at universities in the United States and called for an end to police action against them.

"We call for a halt to the crackdown on voices advocating for peace and freedom," Sadr said in a statement.

"The voice of American universities demanding an end to Zionist terrorism is our voice."

Sadr once led a militia fighting American forces following the 2003 US-led invasion that toppled dictator Saddam Hussein.

A British ship to house hundreds of US troops building a jetty to boost aid deliveries to Gaza has set sail from Cyprus, a UK defence source said Saturday.

Royal Navy support ship Cardigan Bay will assist the international effort to construct the temporary floating pier, which is set to be completed early next month, the Pentagon said.

The pier will initially facilitate the delivery of 90 truckloads of international aid a day into Gaza, rising to up to 150 truckloads once fully operational, according to US estimates.

Between six and eight Palestinian athletes are expected to compete at the Paris Olympics, with some set to be invited by the International Olympic Committee (IOC) even if they fail to qualify, its head Thomas Bach said.

Bach told AFP on Friday that qualification events for the Paris Games, which start on July 26, were ongoing for a number of sports.

Hamas said Saturday it was studying Israel's latest counterproposal for a Gaza ceasefire, a day after media reports said a delegation from mediator Egypt was in Israel trying to jump-start stalled negotiations.

The armed wing of Hamas also released video footage of two men held hostage in Gaza, identified by Israeli campaign group the Hostages and Missing Families Forum as Keith Siegel and Omri Miran.

A UN probe into Israeli allegations that 19 members of the UN agency for Palestinian refugees participated in the October 7 Hamas attacks has closed one case due to the absence of any evidence from Israel and suspended four others, UN spokesman Stephane Dujarric said Friday.

UNRWA was swept into controversy in January when Israel accused 12 of its 30,000 employees of being involved in the shocking cross-border attack, which led to the deaths of around 1,160 people -- mostly civilians -- according to an AFP count based on official Israeli figures.

Israel's war against Hamas has sparked anger and division around the world, including on US campuses, where some Jewish students feel targeted and abused while others have taken leading roles in pro-Palestinian demonstrations.

"A lot of people feel really unsafe," says Eli Sanchez, a Jewish 20-year-old economics major at the University of California, Los Angeles, as pro-Palestinian protests upend college life.

A rare meeting between Turkish President Recep Tayyip Erdogan and his US counterpart Joe Biden at the White House has been postponed, a Turkish official said Friday, amid tensions over the Gaza war.

The talks, previously scheduled for May 9, would be the first White House meeting between the two leaders, who last met on the sidelines of the NATO summit in Lithuania in July.

"The visit planned for May 9 was postponed because of a change in Erdogan's programme," the official told AFP, speaking on condition of anonymity.