Officials: Freed hostage's driver ignored warnings
Italian agent killed, others wounded in checkpoint shooting
A look at growing public resentment of insurgents in Iraq.
Saddam's half-brother and four others to face human rights trials.
A look at one way the Iraqi government is dealing with insurgent infiltrators.
BAGHDAD, Iraq (CNN) -- U.S. soldiers attempted to warn the occupants of a car carrying a freed Italian journalist before troops opened fire, killing a bodyguard and wounding the reporter, multinational officials said Friday night.
Giuliana Sgrena, a 56-year-old reporter for the leftist Italian newspaper Il Manifesto, and three Italian security officers were in a car headed to Baghdad International Airport when they approached a checkpoint, Italian Prime Minister Silvio Berlusconi said. (Full story)
Nicola Calipari was shielding Sgrena when he was killed, Berlusconi said.
Berlusconi said Sgrena had shrapnel in her left shoulder, and U.S. military officials said she was taken to a military hospital.
One agent was seriously wounded, and the other was shot in the leg and refused to go to a hospital, Italian news agencies reported.
President Bush called Berlusconi on Friday night from Air Force One to express his regrets and pledge a full investigation.
According to a multinational forces statement, the car approached the checkpoint at high speed about 9 p.m. (1 p.m. ET)
U.S. troops "attempted to warn the driver to stop by hand and arm signals, flashing white lights, and firing warning shots in front of the car," the statement said. "When the driver didn't stop, the soldiers shot into the engine block, which stopped the vehicle."
Sgrena was kidnapped February 4 outside a mosque in Baghdad. Italian officials did not say how she was freed Friday.
Berlusconi said the two other people in the car contacted his office after the incident.
"They were in disbelief at the fatality at the end of a brilliantly concluded operation," he said.
Berlusconi said though that effort was "concluded positively," the death of Calipari, who was married with two children, brings grief.
"Something that was a joy for all of us ... that I believe brought us all happiness, had to be transformed to a profound sadness for the loss of a person that had behaved ... with valor," he said.
Berlusconi said he called U.S. Ambassador Mel Sembler to his office in Rome for an explanation of the shooting. He said Sembler will have to "clarify" the behavior of the troops.
"Someone will have to take responsibility," he said.
A State Department spokeswoman said Sembler and Assistant Secretary of State William Burns called Italy's ambassador to the United States, Sergio Vento, to offer "U.S. condolences and any assistance the U.S. can provide."
Four soldiers killed
Four U.S. soldiers attached to the 1st Marine Expeditionary Force were killed Friday in western Anbar province, the U.S. military said.
The number of troops who have died in the Iraq war is 1,506, of which 1,151 have died in combat.
Nearly two weeks ago, U.S. forces began Operation River Blitz in the violent province in an attempt to root out insurgents.
A huge swath of land that takes up nearly one-third of the country, Anbar is dotted with Sunni towns along the Euphrates River west of Baghdad to the Syrian border.
Police chief killed
Earlier Friday, attackers killed an Iraqi police chief, multinational forces officials said.
Col. Ghaib Hadab Zarib, the al-Budair police chief, was found dead near his home, about 45 kilometers (28 miles) east of Diwaniya, authorities said.
The gunmen shot him using an assault rifle and fled in a car, officials said.
One woman apparently was wounded in the attack.
On Thursday, gunmen tried to assassinate another police chief.
Col. Mou'ness Saeed, chief of al-Mouqdad police station in Kirkuk, was standing outside his car in southern Kirkuk with his guards late Thursday when gunmen opened fire from a vehicle driving by, Kirkuk police Chief Maj. Gen. Torhan Abdul Rahman said. The incident was the third assassination attempt on Saeed.
One of Saeed's guards was killed and a second critically wounded, but Saeed was unharmed.
CNN's Alessio Vinci and Elise Labott contributed to this report.