Ranks of Hamas fighters formed up on Gaza's beachfront on Saturday for the handover of an Israeli-American hostage in a show of force against the dramatic backdrop of breaking waves.

In Gaza City a stage had been erected at a harbour for the handover of Keith Siegel.

Green Hamas and Palestinian flags flapped in a strong sea breeze near a fisherman's wharf.

Earlier, Israeli Yarden Bibas and Franco-Israeli Ofer Kalderon were handed over in a swift and organised ceremony in the war-battered city of Khan Yunis to the south.

Siegel, 65, wore a black tracksuit and dark-grey hat as he was escorted quickly to the stage by fighters.

He waved to onlookers and cameras, as hostages being freed have been told to do by their captors, before being handed over to the Red Cross.

The occupational therapist seized from his home, along with his wife Aviva who was released during a truce in November 2023, appeared to have some difficulty moving as he mounted the stage.

Before Siegel's release, ordered lines of scores of heavily armed militants, only their eyes visible through masks, flanked the platform.

On a row of pickups, some fighters carried RPGs (rocket-propelled-grenades) and other weapons.

Slain commanders

On the platform itself, militants held up portraits of the group's slain leaders including Mohammed Deif, its military chief accused by Israel of being one of the masterminds behind the 7 October 2023, attack on Israel and whose death was confirmed by Hamas on Thursday.

"We are the men of Mohammed Deif," the Hamas fighters chanted as they brandished their weapons.

Ahead of the two exchanges in Khan Yunis in southern Gaza and Gaza City to the north, scores of Hamas fighters, most wearing military fatigues, stood guard, apparently to control onlookers.

The arrangements for Saturday's hostage release appeared in stark contrast with scenes during Thursday's exchange in Khan Yunis, which was condemned by Israeli Prime Minister Benjamin Netanyahu.

Only after Siegel had left the handover site in a Red Cross vehicle were crowds permitted to move towards the stage.

Onlookers, many of them children, paused to take selfies with Hamas fighters and mingled in the port, waving Palestinian flags.

Bibas and Kalderon were handed over quickly in devastated Khan Yunis, where many buildings have been destroyed in 15 months of war between Israel and Palestinian militants.

Handover formalities

Bibas, the father of the two youngest hostages — Kfir, whose second birthday fell in January, and his older brother Ariel, who turned five in August — was urged to wave to a Hamas cameraman as he held a certificate confirming his release. 

The 35-year-old, whose wife and two children Hamas has declared dead, although Israel has not confirmed their deaths, frowned as he took to the stage and looked straight ahead during the now familiar handover formalities endured by other hostages being released.

Kalderon, 54, seized along with his son Erez, 12, and daughter Sahar, 16, from Nir Oz kibbutz and who were released in a first truce last year, wore a military-green tracksuit as he took to the stage.

He too was instructed to wave before he joined the Red Cross officials. 

An assault rifle, apparently captured from Israeli forces during the fighting in Gaza, had been placed on the table where Red Cross officials exchanged paperwork with a Hamas official to verify that the two men had changed hands.