Updated

The FBI has joined the investigation of a series of kidnappings that have targeted dozens of foreigners in Iraq in the past 10 days, a coalition spokesman said Tuesday.

The most recent reported abductions were of four Italian security guards working for a U.S.-based company and a French TV journalist.

The wave of kidnappings by Iraqi insurgents has left at least 22 foreigners held hostage, including Thomas Hamill (search), a 43-year-old truck driver from Macon, Miss., and three Japanese whose captors threatened to burn them alive if Tokyo didn't withdraw its troops.

But the figures varied; coalition spokesman Dan Senor (search) said Tuesday that 40 people were currently being held from a dozen countries.

Senor said the U.S.-led coalition would not negotiate with "terrorists or kidnappers" to gain the hostages' release. He would not comment on efforts to free the captives.

"The FBI is working with coalition forces and Iraqi security forces to seek out the hostage-takers and the hostages," Senor said. "We have a number of other law enforcement agencies from the international community who are working on this."

The four Italians were reported missing Tuesday, and an Arab satellite TV broadcaster said they had been kidnapped.

The Italian Foreign Ministry said its civilians worked for the U.S.-based DTS LLC Security (search) company and were first reported missing Monday. The Italian news agency AGI and other reports said they were seized in Fallujah, 35 miles west of Baghdad.

Al-Jazeera broadcast a video showing four Italians sitting on the floor holding passports. Behind them were men with machine guns.

The kidnappers demanded the Italian government apologize for insulting Islam and Muslims, Al-Jazeera said. They also want Italy, which has 3,000 troops in Iraq, to withdraw its forces.

Italian Premier Silvio Berlusconi ruled out a troop withdrawal.

"The peace mission of the Italian soldiers in Iraq, in line with the international commitments that have been taken on, is absolutely not in question," he said.

Italy has been a strong supporter of the U.S.-led war in Iraq. It did not send combat troops, but a contingent based in the southern town of Nasiriyah is helping with reconstruction.

The French government demanded the immediate release of Alexandre Jordanov, a journalist for Capa Television in Paris, who was seized Sunday as he was videotaping an attack on an American military convoy.

Franck Duprat, a television editor who worked with Jordanov on an investigative television show called "The Real News," said he disappeared on the road south of Baghdad.

Three Czech journalists feared kidnapped Sunday are fine and could be released as early as Wednesday, Iraqi Minister of Culture Mofeed al-Jazaeri told Czech television from Baghdad.

The three reporters, who were last heard from Sunday, are believed to have been kidnapped while headed toward Jordan. They were identified as Czech Television reporter Michal Kubal and cameraman Petr Klima and Czech Radio reporter Vit Pohanka.

Hamill and six other civilian employees of a subsidiary of the  Halliburton Co. (search), were reported missing after their convoy was ambushed Friday west of Baghdad. Halliburton would not say if the six others were U.S. citizens or from a third country.

The Defense Department also said two soldiers were missing from the ambush: Sgt. Elmer C. Krause, 40, of Greensboro, N.C., and Pfc. Keith M. Maupin, 20, of Batavia, Ohio. Both were assigned to the Army Reserves 724th Transportation Company, Bartonville, Ill.

On Tuesday, eight employees of a Russian energy company were released after being seized by masked gunmen who broke into their house in Baghdad. The five Ukrainians and three Russians spent less than a day in captivity, the Russian Foreign Ministry said.