Some of the activists detained while trying to reach Gaza by sea have returned to their home countries to describe mistreatment at the hands of Israeli guards, allegations that Israel denies.
Some 450 activists were arrested as Israeli forces intercepted the Global Sumud Flotilla, a fleet of 42 boats seeking to break Israel's naval blockade of Gaza and deliver a symbolic amount of aid to the famine-stricken territory. Those detained between Wednesday and Friday were brought to Israel, where many remain in prison.
Israel's Foreign Affairs Ministry said it offered voluntary deportation to all of the activists and that those who remain in detention chose to stay there in order to go through a legal deportation process.
On his return at Rome's Fiumicino Airport late Saturday, Italian journalist Saverio Tommasi said Israeli soldiers withheld medicine and treated prisoners "like monkeys."
The ministry called the allegations of mistreatment "brazen lies."
Among those detained were Swedish activist Greta Thunberg, Nelson Mandela's grandson Mandla Mandela and several European lawmakers.
This image taken from video released by Israel's Foreign Affairs Ministry claims to show activist Greta Thunberg, right, as she is removed after the Israeli navy intercepted the flotilla carrying humanitarian aid to Gaza on Wednesday. (Israeli Foreign Affairs Ministry/The Associated Press)Tommasi said Thunberg was singled out by Israeli forces after being arrested.
"We also saw Greta Thunberg at the port, in that case with her arms tied and an Israeli flag next to her, just a mockery," he said. "Let's say the mockery was part of the verbal and psychological violence they always carried out, in order to demean, ridicule and laugh in situations where there is nothing to laugh about."
In a statement on social media, the ministry said all detainees' legal rights had been "fully upheld," adding that Thunberg had not complained about the "ludicrous and baseless allegations — because they never occurred."
The interception of the flotilla came as U.S. President Donald Trump attempted to broker a fresh ceasefire initiative in Gaza, as he ordered Israel to stop bombing the enclave. Israel said it had accepted Trump's proposal, and Hamas has said it accepts some aspects. Negotiators are expected in Cairo on Monday.
PHOTOS | Hundreds of thousands rally in worldwide in support of Gaza, aid flotilla activists:Another Italian journalist, Lorenzo D'Agostino, said detainees were repeatedly woken during the two nights he spent behind bars. They were also intimidated with dogs and by soldiers pointing the laser sights of their guns at prisoners "to scare us," he said after landing at Istanbul Airport, where 137 activists from 13 countries arrived from Israel on Saturday.
D'Agostino also said his belongings and money had been "stolen by the Israelis."
Activist Paolo De Montis described being crammed into a prison van for hours with his hands secured by zip ties.
"Constant stress and humiliation," he said. "You weren't allowed to look them in the face, always had to keep your head down, and when I did look up, a man ... came and shook me and slapped me on the back of the head. They forced us to stay on our knees for four hours."
In a statement, far-right Israeli National Security Minister Itamar Ben-Gvir said he was "proud" of the way staff behaved at Ketziot prison, a facility in the Negev desert.
"I was proud that we treat the 'flotilla activists' as supporters of terrorism. Anyone who supports terrorism is a terrorist and deserves the conditions of terrorists," he said.
"If any of them thought they would come here and receive a red carpet and trumpets — they were mistaken. They should get a good feel for the conditions in Ketziot prison and think twice before they approach Israel again."
WATCH | Israel detains 2 Canadians on Gaza-bound flotilla:Israeli forces intercepted dozens of vessels belonging to the Global Sumud Flotilla (GSF) carrying foreign activists and humanitarian aid bound for Gaza, the flotilla's organizers said Thursday. This is the latest attempt to break an Israeli blockade and deliver supplies to the war-torn Palestinian territory.The arrests led to criticism from several governments, including Turkey, Colombia and Pakistan. Greece, which had 27 of its nationals in Israeli custody, issued a "strong written protest" to Israel over the "unacceptable and inappropriate behaviour of an Israeli minister."
The complaint is thought to refer to footage of Ben-Gvir upbraiding the activists for supporting "terrorism" and mocking their aid initiative after they were brought ashore at the southern port of Ashdod on Friday.
The Swedish Foreign Affairs Ministry said it had "acted intensively to ensure that the detained Swedes' rights are observed."
The interception of the flotilla also led to large-scale demonstrations in cities around the world.