The body of an Italian pro-Palestinian activist abducted a few hours earlier by Islamic extremists has been found hanged in a Gaza City house, the Hamas government said early Friday.

The officials said Hamas police stormed an apartment in Gaza City belonging to a member of the extremist group that released a video of the activist. Hamas police said they found the man dead after he was hanged.

The International Solidarity Movement had identified the kidnapped activist as Vittorio Arrigoni, 36, a member from Italy. An Italian doctor was on his way from Israel to examine the body, a Hamas official said.

Gaza police were surrounding the small house where the clash took place. A police officer said the body was inside. Police said two people were arrested in another location in connection with the abduction, and a third was being sought.

In a statement, the Hamas Interior Ministry said the man was killed shortly after he was abducted at midday Thursday. Ministry spokesman Ehab al-Ghussein said he was killed "in an awful way." He said the kidnappers planned from the beginning to kill him, not to trade him for captives.

The Interior Ministry spokesman said a member of the militant group led them to the house. He did not name the group. A ministry statement denounced the killing as "a crime that does not reflect the values, morals. religion and customs" of the people of Gaza.

This was the first kidnapping of a foreigner since Hamas overran the Gaza Strip in 2007.

The video released Thursday showed a man with a thick black blindfold and a large bruise on his face. Apparently seated, he was held in front of the camera by an unseen person.

In a message on the video, the extremist group that calls itself Monotheism and Holy War demanded that Hamas free its leader, arrested in early March, and two other members whose names had not been previously known.

Sheikh Abu Walid-al-Maqdasi, the leader of the group, was arrested in a crowded beachside neighborhood of Gaza City last month.

Early Friday, the group posted a statement on its website denying responsibility for the abduction.

Arrigoni had not been heard from in the past 24 hours, said ISM co-founder Huweida Arraf.

In the past, all foreign kidnap victims in Gaza had been released unharmed.

Before the body was found, the Italian Foreign Ministry said in a statement that it was aware of the kidnapping, was in touch with Arrigoni's family and was taking steps to ensure his safety. "Foreign Minister Franco Frattini is in touch with diplomats in the country and is following the situation with great attention," the statement said.

Hamas itself is a fundamentalist Islamic group, but it faces challenges from even more extremist offshoots of Islam, including Walid-al-Maqdasi's group, that take inspiration from al-Qaida and the world jihad movement. Hamas has denied that al-Qaida has a presence in Gaza.

Kidnappings of foreigners were common before the Hamas takeover. Most of those abducted were foreign correspondents, including Alan Johnston of the BBC, who was abducted and held for 114 days before being freed in July 2007, just after Hamas overran Gaza, expelling forces loyal to Palestinian President Mahmoud Abbas.

ISM operates in the West Bank and Gaza and is known for trying to prevent the Israeli military from carrying out its missions. Arraf said this activist has been going in and out of Gaza for more than two years. He was working with farmers and fishermen.

The ISM incident that got the most attention was the 2003 death of American activist Rachel Corrie, who was crushed by an Israeli military bulldozer in southern Gaza while trying to block its path.