More than 100 pro-Palestinian ​activists aboard boats carrying aid bound for Gaza were taken to the Greek island of Crete on Friday after Israeli forces ‌seized their vessels in international waters near Greece, flotilla organisers said.

The activists were part of a second Global Sumud flotilla, launched in recent months in an attempt to break Israel’s blockade of Gaza by delivering humanitarian assistance. The ships set sail from the Spanish port of Barcelona on April 12.

On Friday, an Israeli army ship transferred 168 members of ​the flotilla crew to Greek boats, which then took them to shore where buses and an ambulance waited for them, organisers said and Reuters ​footage showed.

Israel’s foreign ministry called the flotilla organisers “professional provocateurs” and said: “Israel will not allow the breach of the lawful ⁠naval blockade on Gaza.”

Two activists held

Two activists were detained by Israeli authorities, according to statements from Israel and the organisers of the flotilla, who ​identified them as Saif Abu Keshek, a Spanish national of Palestinian origin, and Brazilian Thiago Avila.

Spain’s Foreign Minister Jose Manuel Albares accused Israel of ​illegally arresting Abu Keshek and demanded his immediate release.

Israel’s foreign ministry said Abu Keshek was suspected of affiliation with a terrorist organisation and Avila was suspected of illegal activity, adding that both would be taken to Israel for questioning.

In a post on their Telegram channel, organisers of the flotilla alleged that activists had been denied adequate food and ​water and “forced to sleep on floors that were deliberately and repeatedly flooded” aboard an Israeli naval vessel, describing their treatment as “40 hours of calculated ​cruelty”.

Read More: Israel intercepts Gaza aid ships in international waters, organisers say

They said some suffered injuries, including broken noses and cracked ribs, when they were kicked and dragged across the deck with their hands tied after they tried ‌to protest ⁠against the detention of their two fellow activists.

There was no immediate comment from Israel on the allegations of mistreatment.

Germany and Italy’s foreign ministries issued a joint statement saying they were following developments with “deep concern”.

Some vessels still trying to reach Gaza

A source who asked not to be identified said that while 22 boats had been intercepted by Israel, 47 others were still sailing off southern Crete and planned to anchor there at some point before continuing ​onwards to Gaza. Each ship is ​carrying about a tonne of food, ⁠medical and other equipment, the source said.

The 22 vessels were seized by Israel late on Wednesday in international waters off Greece’s Peloponnese peninsula, which is hundreds of miles from Gaza, the flotilla’s organisers said. In a statement ​on Thursday, the US State Department threatened “to impose consequences” against those who support the flotilla, which it cast ​as pro-Hamas.

Pro-Palestinian activists say ⁠Israel and the US wrongly conflate their advocacy for Palestinian rights with support for Hamas.

Last October, Israel’s military halted a previous flotilla assembled by the same organisation, arresting Swedish activist Greta Thunberg and more than 450 participants.

Palestinians and international aid bodies say supplies reaching Gaza are still insufficient, despite a ceasefire reached ⁠in October ​that included guarantees of increased aid.

Most of Gaza’s more than two million people have ​been displaced, many now living in bombed-out homes and makeshift tents pitched on open ground, roadsides, or atop the ruins of destroyed buildings.

Israel, which controls all access to the Gaza Strip, denies ​withholding supplies for its residents.