The UK has summoned Israel’s chargé d’affaires as international outrage escalates over a video posted by the national security minister, Itamar Ben-Gvir, in which he is seen taunting activists detained after a Gaza-bound flotilla was intercepted.

The global outcry continued as Israel began releasing hundreds of the activists who attempted to breach Israel’s naval blockade of Gaza and are in the process of deporting them, according to a legal organisation working with the flotilla.

Italy’s foreign minister, Antonio Tajani,, said on Thursday he had asked EU foreign policy chief, Kaja Kallas, to discuss sanctions on Ben-Gvir, “for the unacceptable acts committed against the flotilla, seizing the activists in international waters and subjecting them to harassment and humiliation, in violation of the most basic human rights”.

Poland’s foreign ministry said it was calling for a ban on Ben-Gvir entering the country over the video showing the far-right minister taunting detained flotilla activists who were handcuffed and kneeling.

Britain’s Foreign Office issued a statement harshly denouncing the treatment of the arrested activists.

“This behaviour violates the most basic standards of respect and dignity for people. We are also deeply concerned by the detention conditions depicted and have demanded an explanation from the Israeli authorities. We made clear their obligations to protect the rights of all those involved,” it said.

Human rights groups have documented widespread, systemic torture and abuse of Palestinians in Israeli prisons and detention centres during Israel’s war in Gaza, prompted by the Hamas-led attacks on 7 October 2023.

But the humiliating treatment of the Gaza flotilla activists, has drawn unusually strong international condemnation of Israel, reflecting growing frustration with the country’s policies in Gaza, Lebanon and in its joint war with the US against Iran.

Greece on Thursday also called on Israel immediately to release its nationals, the government spokesperson Pavlos Marinakis said.

The European Council president, Antonio Costa, said he was “appalled” by the way Ben-Gvir had treated aid flotilla members attempting to enter Gaza. “This behaviour is completely unacceptable. We call for their immediate release,” he said.

Italy’s prime minister, Giorgia MeloniTajani, demanded an apology for the activists’ treatment and what she called Israel’s “total disrespect” for Italy’s requests.

Turkey said on Thursday it was sending planes to retrieve its citizens and others who participated in the flotilla, Hakan Fidan, the Turkish foreign minister, said. About 85 Turkish nationals took part in the latest flotilla, according to local media.

The backlash has also prompted criticism within Israel and from the prime minister, Benjamin Netanyahu, who defended the interception of the flotilla but said Ben-Gvir’s treatment of the activists was “not in line with Israel’s values and norms”.

Netanyahu said on Wednesday that he had instructed that the activists be deported “as soon as possible”.

Despite Netanyahu’s comments, Israel has a history of intercepting vessels at sea trying to reach Gaza, including with lethal force. In 2010, nine activists on the MV Mari Marmara were killed when Israeli commandos stormed the ship. A 10th person later died of their wounds.

On Wednesday Gideon Saar, Israel’s foreign minister, criticised Ben-Gvir over the treatment of the activists, saying he had harmed Israel in a “disgraceful display” and undermined the work of Israeli soldiers and diplomats.

“No, you are not the face of Israel,” Saar wrote on X.

The US’s ambassador to Israel, Mike Huckabee – usually an uncritical supporter of Israel – also made a rare criticism of Ben-Gvir, saying that while the flotilla was a “stupid stunt”, Ben-Gvir had “betrayed the dignity” of Israel.

The Israel-based legal advocacy group, the Legal Center for Arab Minority Rights in Israel, also known as Adalah, said on Thursday that all of the international activists were in transit to a civilian airport near the southern Israeli city of Eilat for deportation.

The group said one participant, Zohar Regev, was in a court hearing in the southern city of Ashkelon on charges of illegal entry into Israel and unlawful stay. Regev, who holds Israeli citizenship, has taken part in previous flotillas to Gaza.

Ben-Gvir was appointed security minister by Netanyahu despite a number of convictions, including for incitement to racism and support for a proscribed Jewish terrorist organisation.

The activists’ boats set sail from Spain to Gaza in April, with organisers saying they want to draw renewed attention to the conditions for nearly 2 million Palestinians in the Gaza Strip. Israel stopped 20 vessels from the group on 30 April near the southern Greek island of Crete and forced most of its activists to disembark there.