Vittorio Arrigoni's middle name was Utopia, yet he chose to spend most of the past three years in the hell of Gaza, acting as a human shield for Palestinian fishermen harassed by the Israeli navy and reporting to a worldwide audience.

His "Guerrilla Radio" blog about life in Gaza was required reading among radical circles in Italy and he published passionate newspaper commentaries about the plight of the Palestinian people and the "crimes" of "the Zionist regime in Tel Aviv", which he condemned as "one of the worst apartheid regimes in the world". His final post, published hours before his abduction, and subsequent hanging by gunmen in Gaza, praised the "invisible battle for survival" waged by the smugglers in Gaza's tunnel network under the border with Egypt against Israel's "villainous blockade".

Each blog post by "Vik from Gaza City" ended with the entreaty to "stay human" – also the title of his book about living through Israel's Cast Lead invasion in 2009, when he was one of the few foreign journalists reporting from inside Gaza. For Palestinian sympathisers around the world, Arrigoni's trademark curly pipe, rugged good looks and facial piercings became the human face of Gaza.

Arrigoni was born in Besana Brianza, near Milan, 36 years ago and said rebellion ran in his blood. He had the word muqawama – Arabic for "resistance" – tattooed on his right arm. "I come from a partisan family," he said in a recent interview. "My grandfathers fought and died struggling against an occupation, in Italy it was the Nazi-Fascist one. For this reason probably, in my DNA, my blood, there are particles that push me to struggle for freedom and human rights."

He was on the first Free Gaza boat to break the Israeli blockade in August 2008. A month later he was cut by flying glass after the Israeli navy used water cannon on a fishing boat where he was acting as a human shield. In November 2008 he was arrested by the Israelis while out with another fishing boat but managed to return to Gaza before Cast Lead began.

Among his friends in the International Solidarity Movement (ISM) and the Free Gaza Movement (FGM), his abduction and murder have left a bewildering sense of bereavement equal to the deaths of Rachel Corrie and Tim Hurndall, two activists killed by Israeli soldiers. Hundreds of ISM activists organised rallies in Ramallah and Gaza yesterday to mourn their friend. Several gatherings were also held in Italy.

"It's unbelievable," said Huwaida Arraf, a co-founder of the ISM. "He was more Palestinian than the criminals that killed him."

Greta Berlin, a founder of the FGM, said Arrigoni's death would not derail the struggle of foreign activists, who would remain in Gaza. The kidnapping came a week after the assassination of Juliano Mer-Khamis, a Palestinian-Israeli theatre director in Jenin.