Abukeshek was detained alongside Brazilian activist Thiago Ávila after the Israeli navy stopped the humanitarian vessel, while dozens of other activists were intercepted by the Greek coast guard and taken to the island of Crete, according to officials and legal representatives.

Spanish Foreign Minister José Manuel Albares described the detention as unlawful and said he had raised the matter directly with his Israeli counterpart.“This is a case of illegal detention in international waters, outside the jurisdiction of Israeli authorities,” Albares said in an interview with Spain’s public radio.

“I have made this clear to my Israeli counterpart.”The Legal Center for Arab Minority Rights in Israel, known as Adalah, said it visited both men at a detention facility in the Israeli port city of Ashkelon and reported that they had begun a hunger strike.

The group said the two activists alleged they had been repeatedly beaten while in custody and were subjected to isolation, prolonged blindfolding and physical assault.“Adalah maintains that the treatment of the two activists, including the use of isolation, prolonged blindfolding and physical beatings, constitutes a grave violation of international law,” the organization said in a statement.

Israel’s Foreign Ministry said in an online post that Abukeshek and Ávila were being questioned over possible links to the Palestinian militant group Hamas and confirmed that both had been granted consular access.

The detention has added fresh strain to already tense relations between Israel and Spain, one of Europe’s most vocal critics of Israel’s military campaign in Gaza.Spain formally recognized Palestinian statehood in 2024, a move that triggered strong objections from Israel and widened diplomatic friction between the two governments.

Prime Minister Pedro Sánchez intensified criticism on Friday during a campaign event ahead of regional elections in southern Spain, directly addressing Israeli Prime Minister Benjamin Netanyahu over the detention.“Now that Netanyahu has taken foreign citizens, including a Spanish national, and brought them to Israel, I have a few things to say to Prime Minister Netanyahu,” Sánchez told supporters of his Socialist Party.

“First, Spain will always protect its citizens. Second, we will always uphold international law — and this is yet another violation of it,” he said. “And third, we demand the release of the Spanish citizen who has been illegally detained by the Netanyahu government.”

The case has drawn wider attention across Europe as international activists continue attempts to deliver humanitarian aid to Gaza amid the prolonged conflict and worsening humanitarian conditions in the enclave.