Four bodies have been found in Iraq, possibly the remains of private contractors missing since an assault on their convoy outside Baghdad amid a wave of kidnappings of at least 22 foreigners.

A State Department official on Tuesday confirmed the discovery of the bodies, but the private contractor Halliburton (search) said it did not know whether the dead were its missing employees. Initial reports said the four bodies were mutilated, but those reports were not confirmed, the official said.

NBC News reported that the four bodies were in a shallow grave between Fallujah and Abu Ghraib, scene of the convoy attack, and that U.S. officials were led to the grave by an Iraqi.

Two U.S. soldiers and seven employees of Halliburton subsidiary Kellogg, Brown and Root (search) have been missing since their convoy was attacked Friday on the main highway west of Baghdad, between the district of Abu Ghraib and the central city of Fallujah.

The roads west of Baghdad have been a site of many of the kidnappings since the bloody fighting broke out across Iraq this month. Some abductions have also occurred in the south.

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

A U.S. spokesman said 40 foreigners from 12 countries were currently held by kidnappers — though an Associated Press count put the number at 22.

The State Department official, speaking on condition of anonymity, said the four bodies had not yet been identified. It was unclear when the bodies were found.

A spokeswoman for Halliburton Co., the major U.S. contractor in Iraq, said the firm also was aware that remains had been recovered but said it was not confirmed that they were those of its employees.

"We are not yet certain of the identification of these brave individuals, and no matter who they are, we at Halliburton are saddened to learn of these deaths," the firm said in a statement.

One of the seven missing employees — Thomas Hamill, a 43-year-old truck driver from Macon, Miss. — is known to have been abducted. His captors have threatened to kill and mutilate him unless U.S. troops ended their assault on Fallujah. The deadline passed Sunday with no word on his fate. Halliburton would not say if the six others were U.S. citizens or from elsewhere.

The FBI has joined the investigation of the kidnappings, coalition spokesman Dan Senor said in Baghdad on Tuesday. Among the captives are three Japanese whose kidnappers threatened to burn them alive if Tokyo didn't withdraw its troops.

Senor said the U.S.-led coalition would not negotiate with "terrorists or kidnappers." 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.

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.

The four Italians work for the U.S.-based DTS LLC Security company and were first reported missing Monday, the Foreign Ministry said. The Italian news agency AGI and other reports said they were seized in Fallujah.

Italian Premier Silvio Berlusconi, a strong supporter of the U.S.-led war in Iraq, ruled out a withdrawal of troops based in the southern city of Nasiriyah.

"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.

The French government demanded the immediate release of Alexandre Jordanov, a journalist for Capa Television in Paris, who was seized Sunday while 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 on a road that goes through Abu Ghraib. They were identified as Czech Television reporter Michal Kubal and cameraman Petr Klima and Czech Radio reporter Vit Pohanka.

On Tuesday, five Ukrainian and three Russian employees of a Russian energy company were released after being seized by masked gunmen who broke into their house in Baghdad.