Image from Al-Jazeera broadcast Tuesday shows two of four hostages

Terrorist kidnappers threatened to kill four Christian peace activists unless demands are met by Thursday, according to a videotape and statement broadcast by the Arab satellite network Al-Jazeera.

The kidnappers, who have identified themselves as the Swords of Righteousness Brigade, demand the U.S. and Iraqi governments release all prisoners held in detention centers.

The tape showed all four hostages, Tom Fox, 54, of Clearbrook, Va.; Norman Kember, 74, of London; and James Loney, 41, and Harmeet Singh Sooden, 32, of Canada.

The four, members of the activist group Christian Peacemaker Teams, were kidnapped at gunpoint Saturday in Baghdad and shown in a video on Al-Jazeera television news Tuesday. The kidnappers accused them of being spies.

In the latest video, one clip showed the two Canadians eating from plates of sweets and another showed the British and American hostages speaking to the camera but without sound.

Al Jazeera said the two men were calling on the U.S. and British governments to withdraw from Iraq.

In an interview from Baghdad earlier this week, a Canadian member of Christian Peacemaker Teams, Greg Rollins, called the situation "hugely worrisome."

"We're not panicking because we just know the dangers of panicking," Rollins told The Canadian Press.

The group contacted Arab and Muslim friends, urging them to make make it clear in their communities that the hostages are not spies and that Christian Peacemaker Teams opposes the "American occupation of Iraq," reported the National Post.

The Canadian paper said that tactic appeared to pay off yesterday when the Association of Muslim Scholars, a group of influential Sunni clerics in Iraq, called for release of the men to recognize their "good efforts in helping those in need."

Christian Peacemaker Teams has issued a statement saying it opposes using violence to free hostages.