Giuliana Sgrena Was set free today by her captors It was a miracle. The Lord heard your prayers and Your prayers brought her home

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. The other two agents were wounded, he said, but U.S. officials said only one person other than Sgrena was wounded.

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

Giuliana Sgrena Was set free today by her captors It was a miracle. The Lord heard your prayers and Your prayers brought her home

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. The other two agents were wounded, he said, but U.S. officials said only one person other than Sgrena was wounded.

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."

The statement said the other wounded person was a man who was treated at the scene but refused to go to the hospital.

Berlusconi said she had shrapnel in her left shoulder, and U.S. military officials said she was taken to a military hospital.

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.

The White House said President Bush was briefed on the incident.

"We deeply regret the loss of life," said spokesman Scott McClellan, at an event with Bush at the University of Notre Dame.

"Our thoughts and prayers are with the Italian citizen killed and his family. It's a matter that's still under investigation."

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.