Footage on the group’s Facebook page posted on Thursday showed people aboard a boat with their hands in the air.
Near the end of the clip, armed soldiers appear to board the boat amid shouts of “Don’t move”.
The group said two other New Zealanders, Mousa Taher and Jay O’Connor, were also taken into custody.
A media release from the group said the boat Blondel and Janssen were aboard was in international waters and the interception of the craft was illegal under international law.
“The Global Sumud Flotilla sails lawfully under Article 87 of UNCLOS and customary international law.
“We demand that the New Zealand Government takes all necessary measures to protect New Zealand citizens Mousa Taher and Jay O’Connor and ensure their safety,” it said.
The group was calling on the Government to issue a diplomatic confirmation of the humanitarian status of the flotilla and condemn attacks against it.
An MFAT spokesperson said, “Consular officials are seeking further information on the situation, including if any New Zealander has been detained, the basis for their detention, and our expectations regarding their treatment and that Israel acts in accordance with international law at all times. The ministry will also convey this to Israel’s Ambassador to New Zealand,” the spokesperson said.
They said a long-standing “do not travel” advisory for Gaza was in place warning New Zealanders “against any attempt to enter Gaza by sea in breach of Israeli restrictions, including as part of efforts to deliver aid”.
“Participants in previous flotillas have been detained and/or deported by Israel. Reports from some of those individuals have alleged ill-treatment by Israeli authorities, including limited availability of food, water and medicine in detention facilities. There may be additional legal consequences for those who have sought to illegally enter Israeli waters previously.
“These issues are among the reasons why we have advised New Zealanders – repeatedly and over a long period of time – against participating in any flotilla activity. They are putting their safety at risk. As New Zealand does not have an embassy in Israel, our ability to provide consular services there is limited,” the spokesperson said.
The interception comes after three New Zealanders, Rana Hamida, Youssef Sammour and teenager Samuel Leason, were detained from a similar flotilla in early October 2025.
The trio was deported and returned to New Zealand on October 8 amid claims of poor treatment by Israeli authorities.
Israel’s foreign ministry denied the claims and said detainees’ rights were upheld, but Hamida and Sammour said conditions were harsh.
“We were there for almost a week, more or less, and we were treated like crap, to be honest,” Sammour said. “We were treated like animals.”
-RNZ
