PARIS: Cracked bones, humiliation, sexual assault: Pro-Palestinian activists recounted the abuse they say they suffered from Israeli authorities for taking part in a Gaza-bound aid flotilla last month, which has sparked multiple investigations and international outcry.

France, Italy and Australia have launched probes into the allegations of abuse, which Israeli authorities deny, after more than 430 activists from around the world were detained during the latest attempt by an aid flotilla to break the blockade of the war-battered Gaza Strip.

French nationals Meriem Hadjal, Noe Tissot and Malika Baouya were on the boat Peluxo carrying school supplies, infant formula and medicines when Israeli speedboats intercepted them in international waters.

The activists said they were taken from the boat and violently herded together at sea onto what some called the "torture prison ship."

"I was dragged by the arm and lifted with my hands tied behind my back. I screamed in pain, I thought my arm had been torn off," said nurse Baouya.

"We walked with our heads down, hands behind our necks. We were made to lie on the floor, in stagnant seawater. Men were tased," she added.

Stripped to little clothing and fitted with numbered wristbands, the activists, backs bent and limbs shackled, say they were led one by one towards a dark container.

'Afraid they would kill me'

"When the door opened, I saw a fellow prisoner lying on the floor with his trousers down," said Hadjal, 38.

"A soldier started groping my breasts... I was slapped hard. Then again. Some soldiers tried to push me towards the back of the container. I was afraid they would kill me."

Baouya said she saw an activist on the ground being beaten before three men grabbed her.

One soldier "lifted me by my hair," while another "tried to rip off my underwear," she said.

An Israeli military official told AFP that the flotilla members were under the guard of a special unit of the country's prison service.

"A designated area was established with all of the necessities for the participants aboard the landing craft and secured by special Israel Prison Service personnel," the official said.

Israel's penitentiary service did not respond to AFP's requests for comment.

Speaking to AFP in Melbourne, Australia, activist Violet Coco said soldiers had laughed as they "bashed" her, hitting her in the head and kicking her repeatedly.

Her hand was injured as she tried to protect herself from their blows, she said.

"They were groping into my private parts, and I ended up with bruises on my breasts and other places."

The activists were confined for several days to a part of the ship's deck surrounded by containers topped with barbed wire, visible in a highly criticised video released by Israel's far-right National Security Minister, Itamar Ben Gvir.

There, Baouya, who says she suffered a cervical spine fracture after the ordeal, was with "around a hundred others with dishevelled hair and bloodied faces."

Hadjal, who says her foot was injured, said she saw another detainee "come out of the torture container with a swollen face, in a state of shock."

The activists said they slept on the freezing metal and wood floors of the containers, lacking water, hygiene and food, as seawater seeped everywhere.

They accused soldiers of aiming stun grenades and rubber bullets at them.

'Speaking out'

The activists were taken ashore in Israel and detained in Ktziot prison, where they said they met further abuse.

Security personnel "were insulting us, making animal noises and hitting us with their rifle butts" as we arrived near the port, 32-year-old Tissot told officers of France's crimes against humanity unit.

Inside a tent, "a soldier landed a massive punch on my head and ribs", cracking one, he said in his official statement.

Back in Germany after his release, 29-year-old social worker Johannes Happel told AFP his head had been "slammed against a tent pole" and he "saw a friend being punched and repeatedly thrown to the ground."

"Cruel, sadistic and inhumane are the adjectives that spring to mind for everything I saw," he added.

Another Australian activist, Neve O'Connor, described being forcefully taken off the boat and thrown onto a concrete floor.

"All you can hear is the Israeli national anthem as they're playing it on repeat," she said. "It's so loud, and you can hear your friends screaming."

"What we experienced, protected by our passports, is just a taste of what Palestinian prisoners go through," said Hadjal, who sees her testimony as "a weapon."

Baouya, who will give evidence in the French investigation, said she and others were "speaking out not for ourselves, but for the Palestinians."

Gaza Flotila

'Inhumane': Gaza flotilla activists recount Israeli detention ordeal