The kidnappers of Italian journalist Enzo Baldoni, taken hostage in Iraq, said they had killed him, al-Jazeera television reported Thursday.

"We have received footage that showed Enzo Baldoni after he was killed," said an al-Jazeera official, who added that the channel had not decided whether to air the video.

He declined to give further details, and there was no way to immediately verify the report.

Italian newspapers said Baldoni and his driver-interpreter were caught in an ambush Friday between Baghdad and Najaf, scene of a Shiite Muslim rebellion. His driver was found dead on Saturday.

On Tuesday, a group calling itself the Islamic Army in Iraq gave Italy 48 hours to withdraw its 2,700 troops from Iraq or, it said, Baldoni would be killed. Italy, which has the third-largest foreign military contingent in the country, refused to bow to the kidnappers' demands. A statement from Prime Minister Silvio Berlusconi's office said Italy would do everything possible to free Baldoni but that its troops would remain in Iraq.

Baldoni, 56, was a reporter for the Milan-based weekly Diario and volunteered for the Red Cross while in Iraq, his daughter, Gabriella Baldoni, said Wednesday. "He was trying to save human lives in Najaf by helping a Red Cross convoy in a spirit of solidarity which has always underscored his thinking and his actions," she told RAI television.

Four other Italians have been taken hostage in Iraq since militants began employing the technique in April to pressure U.S. allies and businesses to leave the country. One of them, a civilian security guard, Fabrizio Quattrocchi, was shot dead. Three others were released.

The Islamic Army in Iraq claimed responsibility for the death of an Iranian diplomat this month.