BAGHDAD, Iraq (AP) _ In the last six days, U.S. troops have shot at Iraqi police, journalists, a wedding party and a top Italian diplomat searching for looted antiquities.

The Americans are under increasing pressure as the guerrilla resistance has stepped up its hit-and-run attacks and is bringing more firepower and sophistication to the fight.

Unsure of who will shoot at them next, the U.S. forces have been involved in ``friendly fire'' attacks in which 10 civilians have been killed in the past two months.

``We are facing an adaptive, asymmetric enemy, and we, of course, are adapting and refining our tactics, techniques and procedures as well,'' Lt. Col. George Krivo, U.S. military spokesman, said Friday.

In areas where resistance is stiffest, the massive response by U.S. soldiers is changing once-neutral residents into outright opponents.

``The killing of the policemen was the turning point for me,'' said Sabah Khalaf, recalling the Sept. 12 friendly-fire killing of eight U.S.-allied Iraqi policemen in Fallujah _ one of the most dangerous cities for American forces.

Soldiers from the 82nd Airborne Division killed the policemen as they chased a highway bandit. The military apologized for that incident and opened a high-level investigation.

``I thought they came as liberators and had hope that they would bring this country freedom,'' said Khalaf, a 31-year-old resident of Fallujah. ``Initially, we were against the police, calling them agents of the Americans. But by killing the police, the Americans showed their true faces. ... I think the attacks against them will increase, and revenge for the dead policemen will be taken.''

In the most recent friendly-fire incident, American soldiers in northern Iraq shot at a car carrying the Italian official heading up U.S. efforts to recover Iraq's looted antiquities. Pietro Cordone, the top Italian diplomat in Iraq, was unhurt, but his Iraqi translator was killed.

Cordone, also the senior adviser for cultural affairs of the U.S. provisional authority, was traveling on the road between Mosul and Tikrit on Thursday when his car was fired on at a U.S. roadblock, according to an Italian Foreign Ministry official, who spoke on condition of anonymity.

The official said American troops fired at the car, killing the translator. The American troops apparently thought the car was trying to run through the checkpoint, the official said.

The Foreign Ministry said U.S. officials had expressed regret over the incident. In Baghdad, the military said it was investigating.

Also Thursday, U.S. soldiers shot up the car of an Associated Press photographer in Khaldiyah during a firefight after an American convoy was hit with a remote-controlled roadside bomb. The photographer, Karim Kadim, and his driver jumped from the car and ran for cover after they saw that a tank had them in its sights. They were fired on as they ran and the car was badly damaged in subsequent shooting. Neither man was hurt.

In the same incident, AP correspondent Tarek al-Issawi was shot at by soldiers using their tank's 50-caliber machine gun. Al-Issawi also escaped injury.

The AP sent a letter of protest to the U.S. military in Baghdad, saying the shootings were unwarranted and put journalists in grave danger. AP urged a thorough investigation and rules of engagement to prevent future attacks on the press.

Late Wednesday in Fallujah, residents said soldiers killed a 14-year-old boy and wounded six people when they opened fire on a wedding party, apparently believing they were under attack when the guests squeezed off celebratory bursts of gunfire. The military said it was investigating.

In mid-August, U.S. forces shot and killed a Reuters television cameraman outside the Abu Ghraib prison, west of Baghdad.

The military keeps no record of Iraqis who have been killed either intentionally or as innocent bystanders in the primarily urban combat.

While most of the country has been relatively calm since major combat ended, Saddam Hussein loyalists in the ``Sunni Triangle'' north and west of Baghdad have taken a huge toll in American lives.

Since May 1, when President Bush declared major fighting at an end, 82 U.S. soldiers have died in combat. Most of those deaths have occurred in Baghdad or to the west in the belt of towns and villages stretching from Fallujah, 30 miles away, to Ramadi, 30 miles farther along the highway that leads to the Jordanian border.

The U.S. commander in Iraq, Lt. Gen. Ricardo Sanchez, said Thursday the coalition was trying to determine if there were any towns and cities where the local Iraqi authorities might be capable of taking over security responsibility from the Americans.

If there were any, the coalition was prepared to withdraw U.S. and other international forces from municipal centers and keep them on the outskirts to back up Iraqi police.

And, in an apparent search for a guide on how to police a hostile population, the U.S. military has shown interest in Israeli computer software instructing soldiers in the West Bank and Gaza, an Israeli military official said.

Using animated graphics and clips from movies such as ``Apocalypse Now,'' the software outlines a ``code of conduct'' for avoiding abuse of civilians while manning roadblocks, searching homes and conducting other activities, said Lt. Col. Amos Guiora, head of the School of Military Law.