An aide to radical Shiite cleric Muqtada al-Sadr (search) denied Friday that the movement's militia was behind the kidnapping of three Japanese in southern Iraq.

On Thursday, a video was released showing the three Japanese — two aid workers and a photojournalist — surrounded by gunmen. The three were seized in southern Iraq, where the al-Mahdi Army (search) has been fighting coalition forces.

But Amer al-Husseini, the cleric's representative in the Sadr City district of Baghdad, told reporters Friday that the group had nothing to do with the kidnapping. "We condemn such acts and we pray for their release," he said.

Also kidnapped this week in the south were a Syrian-born Canadian from Montreal and an Arab from Jerusalem who work for separate aid agencies.

"We're unclear about who adbucted" Canadian Fadi Ihsan Fadel, said Melissa Winkler, a comunications official with the New York-based International Rescue Committee (search), for which Fadel works.

Fadel, 33, was taken captive when 15 militiamen raided a house in the southern city of Najaf on Wednesday, said an official with the organization in Baghdad, speaking on condition of anonymity.

Gunmen in the nearby city of Kufa later told representatives from the organization that they were holding Fadel for unspecified crimes, the official said, speaking on condition of anonymity. Some of the gunmen who raided the Najaf house were seen in the area.

Al-Mahdi Army militiamen control the cities of Kufa and Najaf. Members of the al-Mahdi Army could not be reached for comment.

Television footage of Fadel in captivity showed him along with Nabil Razouk, 30, an Arab who also works for an international aid group.

Razouk's uncle, Anton, told AP his nephew is an Arab Christian who lives in east Jerusalem and is married to a Czech. The uncle also said that Nabil Razouk has an Israeli passport and works for the U.S. Agency for International Development (search) but considers himself to be a Palestinian.

"I want to tell the Iraqis he is not a spy, not for America and not for Israel," Anton Razouk said, pleading for his nephew's safety in an APTN interview Thursday. "He is an Arab, a member of the Arab nation, a Palestinian like me living in Jerusalem under Israeli occupation."

The Palestinian Authority (search) said Friday it would try to win the release of the two men.

A Briton has also been reported missing in Iraq. And seven South Korean missionaries were held briefly before being released Thursday.

Japanese Prime Minister Junichiro Koizumi (search) on Friday denounced the militants' threats to burn the three the Japanese hostages alive as "cowardly" and vowed that Japanese troops would stay in Iraq.

U.S. coalition spokesman Dan Senor on Friday condemned the kidnappings.

"Our message to anybody who would take hostages of any foreign citizen, foreign national, or Iraqi is the same: Obviously, it will not be tolerated. We will not negotiate with any terrorist that takes hostage of any individual and we will seek to capture or kill them."