Israel’s far-right national security minister, Itamar Ben-Gvir, has sparked a diplomatic crisis by publishing footage of Israeli security forces abusing international activists who were detained as they tried to sail to Gaza with aid.

Three activists were taken to hospital as result of Israeli violence, lawyers representing the group said. They were subsequently discharged. Dozens of others have suspected broken ribs, resulting in breathing problems.

“The team reports systemic violations of due process, and widespread physical and psychological abuse by Israeli authorities,” the rights group Adalah said in a statement. There were “a large number of complaints of extreme violence”.

Ben-Gvir’s video drew a rapid and furious response from countries whose citizens were onboard the boats, including the UK, Canada, Germany, the Netherlands, Spain, Ireland, Australia and New Zealand, in many cases from the top of government.

The US ambassador to Israel, Mike Huckabee, one of the country’s staunchest allies, described Ben-Gvir’s behaviour as “despicable” and said the minister had “betrayed the dignity of his nation”.

The video includes images of dozens of men and women kneeling in rows, with their foreheads to the ground and their hands zip-tied behind their back. Ben-Gvir posted it on his social media account with the caption “Welcome to Israel” in English. He appears waving an Israeli flag, mocking and taunting the detainees, including shouting: “The people of Israel live” in the face of one bound man.

Italy’s prime minister, Giorgia Meloni, said the images were “unacceptable”, and demanded the release of all Italian citizens involved, along with an apology for the mistreatment and the display of “total contempt” toward the Italian government.

“It is inadmissible that these demonstrators, including many Italian citizens, are subjected to this treatment that violates human dignity,” Meloni said in a long statement posted on social media.

The Spanish foreign minister called the treatment “monstrous, disgraceful and inhumane”. His British counterpart, Yvette Cooper, said on social media she was “truly appalled” by the video, which “violates the most basic standards of respect and dignity in the way people should be treated”, and added that she was in touch with some of the families of British citizens held by Israel.

Australian foreign minister Penny Wong joined international condemnation of the footage, saying: “The images we have seen are shocking and unacceptable.

“We condemn the actions of Israeli minister Ben-Gvir – who Australia has sanctioned – and the degrading actions of Israeli authorities towards those detained.”

New Zealand’s foreign affairs minister, Winston Peters, instructed the ministry to call in the Israeli ambassador so his “grave concerns” could be directly passed on.

Peters said New Zealand had placed a travel ban on Ben-Gvir in 2025 for “severely and deliberately undermining peace and security, and removing prospects for a two-state solution”. He added: “His latest conduct with respect to the Gaza flotilla, which has been seriously criticised by his own prime minister, is further vindication of that position.”

Israel detained three New Zealanders – Mousa Taher, Hāhona Ormsby and Julien Blondel – after their boats were intercepted while taking part in a flotilla to Gaza, the Global Sumud Flotilla said. Peters said he expected Israel to adhere to its international legal obligations, including in its treatment of the New Zealanders participating in the flotilla.

More than 400 activists from 40 countries, travelling on 50 vessels, took part in the flotilla, organisers said. It set off from Turkey carrying food and other aid, in the latest high-profile attempt to break the Israeli blockade of Gaza.

Seven months after a ceasefire came into force in Gaza, hunger is widespread, most Palestinians live in tents or overcrowded shelters without adequate sanitation or access to clean water, and Israeli attacks are still a near-daily occurrence.

Israeli forces intercepted the flotilla in international waters on Tuesday and brought everyone onboard to Israel.

The South Korean president, Lee Jae Myung, also denounced Israel’s actions, describing them as “way out of line”, and questioned the legal basis for the arrests outside Israeli territorial waters.

Adalah attorneys and volunteer lawyers working with them met hundreds of the activists at Ashdod port, but “severe access restrictions” meant they were not able to see everyone who had been detained.

Detained flotilla members told lawyers they faced violence when their boats were intercepted, on Israeli military boats and during transfer to the port, Adalah said. This included the use of rubber bullets and tasers. Israeli authorities forced the activists into stress positions, forced them to sit on their knees for prolonged periods and forced them to bend double and when being moved around the port.

In addition to physical abuse, detainees “were subjected to severe degradation and sexual harassment and humiliation”, Adalah said. Several women reported that their hijabs were ripped off.

The Israeli military referred requests for comment about the violence detailed by Adalah to the Israeli prison service and the foreign ministry, which did not immediately respond when contacted on Wednesday evening.

The global outrage at the activists’ treatment prompted the Israeli prime minister, Benjamin Netanyahu, to condemn Ben-Gvir within hours of the video being published online.

“The way that minister Ben-Gvir dealt with the flotilla activists is not in line with Israel’s values and norms,” he said, adding that he had ordered the deportation of the group “as soon as possible”.

The Israeli foreign minister, Gideon Saar, launched a more scathing personal attack on the minister. “You knowingly caused harm to our state in this disgraceful display – and not for the first time,” he said in a statement on X. “You are not the face of Israel.”

Ben-Gvir appeared to relish the censure. “Israel has stopped being a pushover,” he replied to Saar.

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

Sari Bashi, director of the rights group Public Committee Against Torture in Israel, said Ben-Gvir’s video reflected a broader culture of impunity.

“To me it’s just an indication of how badly the rights and welfare of detainees have suffered under [Ben-Gvir’s] leadership,” Bashi said. “A prison guard who sees his boss’s boss express pride in the mistreatment of foreign detainees will have no qualms about abusing Palestinian detainees and he won’t even have to be afraid to get caught.

“Ben-Gvir is saying that this behaviour is welcomed and encouraged at the highest level.”

The legal rights group Adalah, which represents some of those detained, said it had “documented similar patterns of ill-treatment against activists in previous flotilla missions, for which Israel faced zero accountability”, and called for the international community to take urgent action to protect activists held by Israel.

The video was released the day after another far-right member of the Israeli cabinet – the finance minister, Bezalel Smotrich – announced that he had ordered the ethnic cleansing of a Palestinian village in response to reports that the international criminal court (ICC) was seeking a warrant for his arrest.

Smotrich called a press conference to attack the ICC and publish an order for the eviction of all residents of Khan al-Ahmar, home to more than 700 people. It lies in the heart of the occupied West Bank, about 6 miles (10km) east of the Old City of Jerusalem, ringed by Israeli settlements.

The ICC’s top prosecutor has requested arrest warrants for Smotrich, Ben-Gvir, Orit Strook, the minister of settlements and national missions, and two Israeli military officials, Haaretz newspaper reported this week.