The father of a Lebanese-born U.S. Marine whose captors in Iraq are threatening to behead him pleaded Monday for his son's release, saying he was not involved in the fight against Iraqi resistance groups.

Cpl. Wassef Ali Hassoun (search) was shown blindfolded, with a sword brandished over his head in a videotape aired Sunday -- the latest in a flurry of new kidnappings and death threats in Iraq just ahead of the handover of power to a new Iraqi government.

Insurgents have threatened to behead a kidnapped Pakistani driver by Wednesday, and the captors of three Turkish hostages say they will kill them Tuesday.

All five hostages -- including Hassoun -- are Muslim. It is not known if their abductions are connected.

"I appeal to the kidnappers and to their conscience and faith to release my son. He is not a fighter. I hope that they will respond favorably to my appeal. May God reward them," Wassef's father, Ali Hassoun, told The Associated Press at his house in the northern Lebanese port city of Tripoli.

The kidnappers claimed to have infiltrated a Marine outpost, lured the younger Hassoun outside and abducted him.

The U.S. military said Hassoun, 24, was last seen June 19 and did not report for duty the next day.

Hassoun had gone "on an unauthorized absence," said Brig. Gen. Mark Kimmitt, the coalition deputy operations chief in Baghdad, giving few details. "Based on his personal situation, there was reason to suspect that he was heading over to Lebanon."

Ali Hassoun sat chain-smoking in his fourth-floor apartment, waiting for word on his son and reading the Quran, Islam's holy book.

Another of his sons, Sami, talked with worried relatives, who said contacts were under way with politicians and Muslim clerics in Lebanon and Islamist groups in Iraq to secure the Marine's release.

"We are trying to send word through all channels that he is Lebanese, Arab and a Muslim," Abdullah Hassoun, a member of the extended family and head of Al-Safira municipality, told the AP.

"He must be released by his kidnappers," he said.

Al-Jazeera television, which aired the video, said the militants demanded the release of all Iraqis "in occupation jails" or the hostage would be killed. They did not set a timeframe.

"We're doing everything we need to be doing at this time to prepare for any future operations in regard to the young Marine," Kimmitt said.

Hassoun is originally from the northern Lebanese town of Al-Safira but lived in Tripoli until he emigrated in the early 1990s to the United States, where he gained citizenship.

He lived with his eldest brother, Mohammad, in the Salt Lake City suburb of West Jordan and later joined the Marines.

"We accept destiny with its good and its bad," Hassoun family friend and spokesman Tarek Nosseir said outside the family's home in West Jordan. "We pray and we plead for his safe release and we ask all people of the world to join us in our prayers."

His kidnappers identified themselves as part of "Islamic Response," the security wing of the "National Islamic Resistance (search) -- 1920 Revolution Brigades." The name refers to the uprising against the British after World War I.

It was unclear whether they or the kidnappers of Pakistani driver, Amjad Hafeez, are connected to Jordanian terror mastermind Abu Musab al-Zarqawi, whose followers claimed responsibility for the kidnapping of the three Turks.

Al-Zarqawi is also believed behind the decapitation deaths of American businessman Nicholas Berg (search) last month and South Korean translator Kim Sun-il last week.

Pakistanis reacted with outrage and grief Monday over Hafeez's kidnapping with some blaming their government for siding with the United States in the war on terrorism and many expressing disbelief that guerrillas would target fellow Muslims.

"I cannot believe it. I never thought Iraqis could be enemies of Pakistanis," said Sumaira Anwar, a 30-year-old housewife in the eastern Pakistani city of Lahore.

Hafeez works as a driver for the U.S. company Kellogg, Brown & Root, a subsidary of Vice President Dick Cheney's former company, Halliburton. Hafeez's captors demand the release of some prisoners held by the Americans.

Dozens of foreigners have been kidnapped in Iraq since early April -- including other Arabs, Pakistanis and Turks. Most have been released, though Berg, Kim, an Italian and a Lebanese were killed.