Hamas says Italian activist abducted in Gaza found dead (VIDEO)

An Italian peace activist has been found dead in the Gaza Strip after becoming the first Westerner abducted by Islamist extremists in the territory for four years, Hamas officials said.

Vittorio Arrigoni, a pro-Palestinian activist for the International Solidarity Movement, was seized on Thursday by a radical group demanding the release of their leader captured last month, the BBC said.

Later in the day he appeared blindfolded on an Internet video released by the Salafi Jihadi, which threatened to kill him unless its demands were met.

The group issued a deadline of Friday evening, but officials from the Hamas, Islamist which governs the territory, said the 36-year-old's strangled body was found in an abandoned building.

Hamas Interior Ministry spokesman Ehab Al-Ghssain told reporters that Arrigoni's body was found after an arrested suspect revealed the location where the Italian was being held.

"The forces moved quickly and wisely to the place but found that the abducted man was killed hours earlier in an ugly manner, according to the pathologist," Ghssain said.

"Their intention from the very beginning was to kill their victim, because the crime took place after a short period of his abduction," he added.

Arrigoni was the first Westerner abducted in Gaza since BBC correspondent Alan Johnston's was held hostage for three months in 2007.

The Los Angeles Times says the kidnapping casts doubt over Hamas' ability to control Gaza against challenges by more radical groups, some with alleged links to Al Qaeda.

Hamas, viewed as a terrorist organization by the United States and Israel, has controlled Gaza since 2007.