One of the four Italian hostages abducted in Iraq has been killed, the Italian foreign minister has said.
Al-Jazeera earlier broadcast pictures of the Italians
The dead man was identified as 36-year-old Fabrizio Quattrocchi.
The Arabic TV station Al-Jazeera said it had video footage of the death, but would not broadcast it, because it was "too gruesome".
Italian Prime Minister Silvio Berlusconi said the killing - the first confirmed hostage death in Iraq - would not affect the peace effort.
"They have destroyed a life, they have not cracked our
values and our efforts for peace," he said in a statement read out on Italian TV.
Foreign Minister Franco Frattini said earlier that the kidnappers were "a group of bandits, not tied organically to any group".
US President George W Bush has also vowed to stay the course as the threat of kidnappings remains.
The US-led coalition says around 40 foreigners are currently held hostage by militants in Iraq.
Mr Berlusconi's office said that an envoy, Gianni Castellaneta, would be sent to the region to try and obtain the release of the three other Italian hostages.
The BBC's Brian Barron in Rome says the government appears to be pinning its hopes on mediation by Iran.
The hostage drama dominated Italian television on Wednesday evening, as it brought together some of the men's relatives and Foreign Minister Frattini.
At one point a relative turned to Mr Frattini and asked "What can we do about this?" - and there was nothing he could say, our correspondent reports.
Russia has announced that on Thursday and Friday it will airlift more than 800 of its nationals and former Soviet citizens from Iraq because of the threat f further abductions.
The Italians, who are security guards working for a US-based company, were abducted on Monday.
The video is said to show the four sitting on the
ground, holding up their passports and surrounded by armed men.
Al-Jazeera apologised for not broadcasting the killing, saying it was "too gruesome", but an official for the TV told Italian television that Quattrocchi had been shot in the back of the neck with a pistol.
The TV also said it had received a statement from the kidnappers, who were members of a group calling itself al-Katibat al-Khadra, or Green Battalion.
They put forward three conditions:
- Mr Berlusconi should apologise for alleged insults against Islam
All Italian troops based in Iraq should be withdrawn
All clerics held by Italian forces should be released.
They also threatened to kill the other three hostages "one by one".
Other governments have advised their citizens to also leave the country.
Philippines President Gloria Arroyo said she would not withdraw the country's small contingent of troops in Iraq but may evacuate Filipino civilians working there, of whom there are thought to be hundreds.
Japan is investigating reports that two more of its citizens have been abducted in addition to three already held.
The foreign ministry in Tokyo was reacting to media reports that two freelance journalists had been abducted outside Baghdad on Wednesday.
The fate of the first three is still unclear.
However, a French journalist kidnapped on Sunday has now been released. Alexandre Jordanov was in good health after his ordeal, French officials said.
Italian forces - the third largest contingent in the US-led coalition - are based in the southern city of Nasiriya, working on reconstruction.
Italy did not send combat troops during the war.
Last November a suicide truck bomb attack in Nasiriya killed 19 Italians - the country's worst single military loss since World War II.