MADRID: Spain on Saturday condemned the "illegal detention" of one of its citizens who was taken to Israel after being seized in an Israeli military operation against a Gaza aid flotilla in international waters.
Saif Abu Keshek "must be released immediately so that he can return to Spain", Spanish Foreign Minister Jose Manuel Albares told Rac1 radio.
"We are facing an illegal detention in international waters, outside any jurisdiction of the Israeli authorities," Albares said.
Israeli forces on Wednesday night intercepted the flotilla, a group of more than 50 vessels seeking to break an Israeli blockade of Gaza to deliver needed supplies.
The vessels were boarded in international waters off Greece. Organisers said armed Israeli personnel smashed equipment on the vessels, leaving them helpless and incommunicado at sea.
Israel said it had removed around 175 activists from the flotilla, but organisers accused Israeli personnel of "kidnapping" 211 people.
Israel released almost all the activists later and they were escorted by the Greek coast guard on Friday to the island of Crete.
But Israel kept Abu Keshek and a Brazilian activist, Thiago Avila. On Saturday, the Israeli foreign ministry said the two were in Israel for "questioning by law enforcement authorities".
The ministry alleged the two were affiliated with an organisation, the Popular Conference for Palestinians Abroad (PCPA), which is under US sanctions for purported links to Hamas.
Albares said that, after requesting information, he had seen no indications of any link between Abu Keshek and Hamas.
Israel controls all entry points to Gaza, which it has kept under a blockade since 2007.
Throughout the war sparked by Hamas's October 2023 attack on Israel, Israel at times cut off the entry of aid entirely, and currently continues to restrict humanitarian aid.
Albares said that Israel had acceded to a Spanish request that Abu Keshek be given a consular visit and "all indications are that we will finally be able to see him".
The foreign minister called Israel's actions "unacceptable", saying: "A state does not conduct itself in this manner: raids in international waters, the forced transfer of citizens who are not its nationals to that other country."
Albares reiterated Madrid's support for the existence of the state of Israel.
"But what Israel must understand is that what we believe for Israel we also believe for Israel's relations with other states: they cannot be based on force," he said.