Palestinians and foreign activists hold banners as they take part in a protest against the killing of Italian activist Vittorio Arrigoni, in the West Bank of Ramallah April 15, 2011. Hamas found the body on Friday of the pro-Palestinian Italian activist who was killed by al Qaeda sympathisers in the Gaza Strip, raising questions about the Islamist group's control over the beleaguered enclave.photo by:Issam Rimawi flash 90

Palestinians and foreign activists hold banners as they take part in a protest against the killing of Italian activist Vittorio Arrigoni, in the West Bank of Ramallah April 15, 2011. Hamas found the body on Friday of the pro-Palestinian Italian activist who was killed by al Qaeda sympathisers in the Gaza Strip, raising questions about the Islamist group's control over the beleaguered enclave.photo by:Issam Rimawi flash 90

A Palestinian woman holds a slogan against the kidnapping and killing of an Italian human rights activist by a Salafist group of radical Islamist, during a protest in Gaza City, on April 15, 2011. International Solidarity Movement member Vittorio Arrigoni, 36, was kidnapped on April 14 by a previously-unknown Salafist group who posted video outlining their demands online. But hours before the 30-hour deadline expired, he was found hanged in an abandoned house in northern Gaza. PHOTO/MOHAMMED OTHMAN flash 90

A Palestinian womans holds a slogan against the kidnapping and killing of an Italian human rights activist by a Salafist group of radical Islamist, during a protest in Gaza City, on April 15, 2011. International Solidarity Movement member Vittorio Arrigoni, 36, was kidnapped on April 14 by a previously-unknown Salafist group who posted video outlining their demands online. But hours before the 30-hour deadline expired, he was found hanged in an abandoned house in northern Gaza. PHOTO/MOHAMMED OTHMAN flash 90

A Palestinian womans holds a slogan against the kidnapping and killing of an Italian human rights activist by a Salafist group of radical Islamist, during a protest in Gaza City, on April 15, 2011. International Solidarity Movement member Vittorio Arrigoni, 36, was kidnapped on April 14 by a previously-unknown Salafist group who posted video outlining their demands online. But hours before the 30-hour deadline expired, he was found hanged in an abandoned house in northern Gaza. PHOTO/MOHAMMED OTHMAN flash 90

A Palestinian womans holds a slogan against the kidnapping and killing of an Italian human rights activist by a Salafist group of radical Islamist, during a protest in Gaza City, on April 15, 2011. International Solidarity Movement member Vittorio Arrigoni, 36, was kidnapped on April 14 by a previously-unknown Salafist group who posted video outlining their demands online. But hours before the 30-hour deadline expired, he was found hanged in an abandoned house in northern Gaza. PHOTO/MOHAMMED OTHMAN flash 90

A Palestinian womans holds a slogan against the kidnapping and killing of an Italian human rights activist by a Salafist group of radical Islamist, during a protest in Gaza City, on April 15, 2011. International Solidarity Movement member Vittorio Arrigoni, 36, was kidnapped on April 14 by a previously-unknown Salafist group who posted video outlining their demands online. But hours before the 30-hour deadline expired, he was found hanged in an abandoned house in northern Gaza. PHOTO/MOHAMMED OTHMAN flash 90

A Palestinian womans holds a slogan against the kidnapping and killing of an Italian human rights activist by a Salafist group of radical Islamist, during a protest in Gaza City, on April 15, 2011. International Solidarity Movement member Vittorio Arrigoni, 36, was kidnapped on April 14 by a previously-unknown Salafist group who posted video outlining their demands online. But hours before the 30-hour deadline expired, he was found hanged in an abandoned house in northern Gaza. PHOTO/MOHAMMED OTHMAN flash 90

Palestinian light candles during a protest against killing of Italian activist Vittorio Arrigoni in Gaza City, 15 April 2011. Hamas authorities in the Gaza Strip condemned as a 'shameful crime' the kidnap and killing of Italian activist Vittorio Arrigoni whose body was found 15 April hours after he had been abducted by radical Islamists. Arrigoni, an Italian activist for the International Solidarity Movement (ISM), was found dead in an abandoned house in the north of the Gaza Strip in the early hours 15 April. Photo/ Mohammed Othman flash 90

Palestinian light candles during a protest against killing of Italian activist Vittorio Arrigoni in Gaza City, 15 April 2011. Hamas authorities in the Gaza Strip condemned as a 'shameful crime' the kidnap and killing of Italian activist Vittorio Arrigoni whose body was found 15 April hours after he had been abducted by radical Islamists. Arrigoni, an Italian activist for the International Solidarity Movement (ISM), was found dead in an abandoned house in the north of the Gaza Strip in the early hours 15 April. Photo/ Mohammed Othman flash 90