Spain's interior ministry did not name the suspect, but described him as a 52-year-old "already convicted for his involvement in the terrorist organisation al-Qaeda".
Air strikes, artillery and machine-gun fire have left the lakeside city of Marawi in the southern Philippines a smouldering wasteland of shattered buildings and bullet-pocked mosques and houses.
Isis continues its campaign of terror, but the group is progressively losing territories due to multinational offensives in Syria and Iraq.
Jac Holmes, 24, had been fighting alongside Kurdish troops to force the Muslim extremists from their stronghold in Raqqa.
The Isis arsenal comprised the latest weapons made in Nato countries, including a UK-made 155 mm howitzer manufactured in 2011.
Photos of the shattered Syrian city of Raqqa after a fierce four-month battle to expel Islamic State (Isis/Daesh).
Syrian Democratic Forces' recapture of Raqqa is an emblematic loss for terrorist group who had designated the city the capital of the so-called Islamic State. But it does not signal the end of Isis.
British Isis recruiter Sally Jones, also known as the White Widow, allegedly tried to recruit a British pizza chef to assassinate the Queen with a home-made bomb in 2015.
Activists say civilians suspected of working with government were shot in the street as militants retreated before Syrian troops and allied militias regained control of the town.
Ziad Doueiri was ordered to appear before a Lebanese military court last month because his previous film was shot in Israel.
In pictures: The siege of Marawi has finally come to an end after one final fierce gunfight with a group of militants holed up in the shattered city.
Sahar's skeletal body weighed four pounds (1.9kg) when she reached the hospital in eastern Ghouta region, where humanitarian access is restricted due to a blockade imposed by the Assad regime.
"There are no more militants in Marawi City," Defense Secretary Delfin Lorenzana said while announcing the end to combat operations in the city.
Al-Omar oilfield is located in the east bank of the Euphrates River in eastern Deir ez-Zor province.
One in five Rohingya children in Bangladesh's refugee camps are "acutely malnourished" and require medical attention, says Unicef report, Outcast and Desperate.
A steady stream of Syria-focused rhetoric from Al-Qaeda shows that the organization has not at all given up on Syria, but is rather trying to reestablish itself.
Chilling photos of bunkers, bombs and bodies inside Raqqa after Syrian Democratic Forces (SDF) fighters liberated the city from Islamic State (Isis/Daesh) militants.
The attacks come just two days after Taliban gunmen stormed a police training centre in eastern Afghanistan, killing at least 74 people.
Opposition leaders are trying to mobilize against efforts to remove an age barrier in the constitution that prevents 73-year-old President Yoweri Museveni from extending his rule when his current term expires in 2021.
"Isis is currently in an 'interim' period focusing on a much bigger endgame," Elaine Duke, US President Donald Trump's acting Secretary of Homeland Security, warned.