An Italian journalist has been seized in Baghdad while interviewing people in the street, Iraqi police have said.
Giuliana Sgrena was abducted while talking to Falluja refugees
Armed men abducted Giuliana Sgrena, 56, from Il Manifesto newspaper, as she spoke to refugees from Falluja near Baghdad University.
Prime Minister Silvio Berlusconi said Italy was trying to secure Ms Sgrena's negotiated release but gave no details.
A militant group said it had carried out the kidnap and gave Italy three days to withdraw its troops from Iraq.
"We... give the Italian government 72 hours to get out of Iraq, otherwise the squadrons will have something else to say in the coming days," said a web statement in the name of the little-known Islamic Jihad Organisation.
Italian officials said they were looking into the claim.
A group using the same name said in September it had killed two female Italian aid workers who were later released by another group.
Ms Sgrena's kidnapping is the latest attack on foreign reporters working in Iraq.
A French woman reporter, Florence Aubenas, and her Iraqi assistant went missing in Iraq in January.
The Italian aid workers, Simona Torretta and Simona Pari, were freed in September, three weeks after they were kidnapped in Baghdad.
Italy denied paying any money or negotiating with the hostage-takers.
Mr Berlusconi on Friday said efforts were under way to secure the release of Ms Sgrena, the eighth Italian to be taken captive in Iraq.
Ms Sgrena was seized at about 1400 (1100 GMT) in the al-Jadriya district in central Baghdad, an Iraqi interior ministry official said.
Journalist and aid worker Enzo Baldoni was killed by his captors
"Men in a minibus blocked their car. They took the journalist and an Iraqi driver who were found in the car and whisked them away to an unknown location," the official told AFP news agency.
Gabrielle Polo, a director of the daily Il Manifesto paper, told AFP Ms Sgrena had been abducted minutes after calling the office to say she was fine.
Italian radio journalist Barbara Schiavulli told her station GRT in Rome that Ms Sgrena had called her mobile phone while the abduction was going on, the Associated Press agency reported.
"I heard shots and people running but I did not hear her speak," Ms Schiavulli said.
"I only heard pistol shots... I heard shots and began to shout 'Giuliana, Giuliana', but she did not reply."
Ms Sgrena, who had been in Baghdad since 23 January, had gone to a mosque near the university to talk to more than 1,000 Falluja refugees who had set up tents there, AFP said.
An Italian journalist and Red Cross aid worker, Enzo Baldoni, was kidnapped on 20 August last year between Baghdad and Najaf.
He was killed by a group calling itself the Islamic Army in Iraq and footage of his death released on a video.
Four Italians were taken hostage in Iraq in April. One of them, civilian security guard Fabrizio Quattrocchi, was later shot dead by his captors, while three were released.