An Italian pro-Palestinian activist has been found dead in the Hamas-governed Gaza Strip hours after being abducted.
Vittorio Arrigoni, 36, was seized on Thursday by a radical group that has been in conflict with Hamas and is seeking the release of its leader.
Police said he was found hanged in a Gaza City house after receiving a tip-off. Two people have been arrested.
Italy denounced the "barbaric murder", calling it an "act of vile and senseless violence".
Mr Arrigoni was the first foreigner kidnapped in Gaza since BBC journalist Alan Johnston was abducted in 2007.
Friends of the activist gathered outside the hospital where his body had been taken on Friday morning.
"He came from across the world, left his country and family and his entire life and came here to break the siege, and we kill him? Why?" asked one of his friends.
Vittorio Arrigoni was seized by Salafist radicals, an Islamist movement itself that considers Hamas as too moderate, BBC Gaza correspondent Jon Donnison says.
The Salafists had threatened to execute Mr Arrigoni by 1400 GMT on Friday unless several prisoners, including their leader, Sheikh Abu Walid al-Maqdasi, were released. Sheikh Maqdasi was arrested by Hamas police last month in Gaza City.
In a video posted on YouTube, Mr Arrigoni appeared to have been beaten and his eyes were covered with thick black tape.
A caption on the video read: "The Italian hostage entered our land only to spread corruption." The video called Italy "the infidel state".
It is not clear why Mr Arrigoni was killed before the given deadline, but the Hamas interior ministry said he had died soon after being abducted.
Ministry spokesman Ehab al-Ghussein said he was killed "in an awful way". (Read more.)
This story is a strange illustration of the division in the Muslim world. Vittorio Arrigoni is an Italian activist campaigning for a Palestinian state. Thus, he is loved by many Muslims. Yet a group of Salafis kidnapped and beat Vittorio, and are now holding him hostage. They released a video earlier today:
Some Muslims and other pro-Palestinian groups are so shocked at Vittorio's kidnapping, they're accusing Israel of framing Muslims for the kidnapping.
(SALEM / GAZA) - Possibly the strongest voice in the years-long struggle to free Palestine, 36-year old Vittorio Arrigoni, a journalist and activist with the International Solidarity Movement, was kidnapped in Gaza.
From what we understand, a Salafi Group in Gaza claims responsibility for the kidnapping. Later in the day, a youtube video surfaced showing Vittotio blind folded and beaten up.
Salafi Jehadis say they are asking Hamas government in Gaza to release Abu Al Waleed Al Maqdisi in 30 hours starting from 11:00 a.m. today or else they would kill him.
One person who knows the steadfast dedication of Vittorio 'Vic' Arrigoni is our writer Ken O'Keefe, also in Gaza, who stated the bottom line on this sad day.
"Who benefits? This is the question we must ask first when something like Vic Arrigoni being kidnapped happens. The answer is, Israel; nobody benefits more than Israel."
"So whether they are false-Muslims or agents of Israel, those that have Vic are serving Israel." (Read more.)