Saif Abu Keshek, a Spanish national, and Brazilian Thiago Avila were detained by Israeli authorities late on Wednesday and brought to Israel, while more ​than 100 other pro-Palestinian activists aboard the boats were taken to the Greek island of Crete.

A court spokesperson confirmed that their remand ⁠had been extended until May 5.

The governments of Spain and Brazil issued a ​joint statement on Friday calling their detention illegal.

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

Israeli authorities requested a ​four-day extension of their arrest on suspicion of offences that include assisting the ​enemy during wartime, contact with a foreign agent, membership in and providing services to a ‌terrorist ⁠organisation, and the transfer of property for a terrorist organisation, said rights group Adalah, which is assisting in the activists’ defence.

Hadeel Abu Salih, the men’s attorney, said that the two deny the allegations. Their arrest was unlawful due ​to a lack of ​jurisdiction, she told ⁠Reuters at the Ashkelon Magistrate’s Court after the hearing, adding that the mission was meant to provide aid to ​civilians in Gaza, not to any militant group.

Abu Salih said ​that Abu ⁠Keshek and Avila were subjected to violence en route to Israel and kept handcuffed and blindfolded until Thursday morning.

The Israeli military did not immediately respond to ⁠a request ​for comment.

Israel’s foreign ministry had on Thursday ​called the flotilla organisers “professional provocateurs”.

“Israel will not allow the breach of the lawful naval blockade on Gaza,” ​it said.