ABUL, Afghanistan The American air campaign in Afghanistan, based on a high-tech, out-of-harm's way strategy, has produced a pattern of mistakes that has killed hundreds of Afghan civilians.

On-site reviews of 11 locations where airstrikes killed upward of 400 civilians suggest that American commanders have sometimes relied on mistaken information from local Afghans. Also, the Americans' preference for airstrikes instead of riskier ground operations has made it harder to discover when the intelligence is wrong.

The reviews, over a six-month period, found that the Pentagon's use of overwhelming force meant that even when true military targets were located, civilians were sometimes killed. The 11 sites visited accounted for many of the principal places where Afghans and human rights groups claim that civilians have been killed.

Pentagon officials say their strategy has evolved in recent months away from airstrikes to the use of ground forces to hunt down remaining fighters for the Taliban and Al Qaeda. Since then, air power has been deployed in mostly a supporting role; still, the effects have often been disastrous.

The American attack this month on villages in Oruzgan Province, where airstrikes killed at least 54 civilians, has crystallized a sense of anger here that threatens to undermine the good will the United States gained by helping to dislodge the Taliban. That anger is threatening to frustrate America's ability to hunt down Taliban and Qaeda forces that still survive.

For the first time, Afghan leaders are demanding a say in how air raids are conducted. They are even hinting that if the mistakes continue, they may limit America's future military activities.

"We have to have to be given a larger role," said Dr. Abdullah, the Afghan foreign minister, in an interview. "If things to not improve, well, I will certainly pray for the Americans and wish them success, but I will no longer be able to take part in this."

The Pentagon often relies on warlords and other local Afghans whose loyalties are unclear in a country riven by decades of war and tribal rivalries. Its critics say the such information is inherently unreliable, and that the Pentagon has too often launched military strikes without a full understanding of what it is they were targeting.

But American military commanders insist they take pains to ensure that that civilians are spared, often verifying their targets with several sources of information. In many of the cases cited here, they insist that they struck valid military targets. In many cases, despite evidence on the ground, they denied that civilians were killed.

Indeed, the American commanders reject the notion that they may be placing too much reliance on Afghan warlords for information, or too much reliance on air power to carry out their strategy.

"We painstakingly assess the potential for injuring civilians or damaging civilian facilities, and positively identify targets before striking," said Col. Ray Shepherd, chief spokesman for the United States Central Command in Tampa, Fla., in an interview.

Nonetheless, American officials acknowledged that the botched strike in Oruzgan has strained relationships with the Afghan government. They said that since the raid, they have changed their procedures. "We want to ensure that coordination with Afghan leaders is complete prior to an action," Colonel Shepherd said.

The war in Afghanistan is not the first time that differences have risen between what pilots believe they hit and what is found on the ground later. Nor is it the first time that questions have risen about civilian casualties of American air attacks.

After 78 days of airstrikes over Serbia in 1999, American military officials conceded that damage to the Yugoslav army was far less extensive than what they had originally believed. In those raids, Human Rights Watch, an American organization, said at least 500 civilians had been killed.

American commanders say they have not kept track of civilian deaths in Afghanistan, but they say their strategy has succeeded at a relatively low cost. Earlier this year, General Tommy R. Franks, the head of Central Command, called the Afghan campaign "the most accurate war ever fought in this nation's history." The military also takes solace in relatively low American casualty numbers, including 37 soldiers killed.

Indeed, the extraordinary accuracy of American bombs since they began falling 10 months ago produced few of the types of disasters that plagued past wars, when bombs aimed at one target hit something else instead. In one of those cases here, last November, an American bomb aimed at a building that was thought to harbor a senior Taliban military commander, Jalaluddin Haqqani, hit a mosque instead.

A reporter visiting the mosque after the strike found evidence to substantiate Afghans' claim that at least 65 civilians died. American military officials acknowledged that the mosque had been struck in error, but a senior American military official said Pentagon records "do not substantiate" the claim of 65 deaths.

Those kinds of incidents have been rare. Instead, the evidence suggests that many civilian victims have been killed by airstrikes hitting precisely the target they were aimed at. The civilians died, the evidence suggests, because they were were targeted by mistake, or because in eagerness to kill Qaeda and Taliban fighters, Americans did not carefully differentiate between civilians and military targets.

Field workers with Global Exchange, an American organization that has sent survey teams into Afghan villages, say they have compiled a list of 812 Afghan civilians who were killed by American airstrikes. They say they expect that number to grow as their survey teams reach more remote villages.

Marla Ruzicka, a Global Exchange field worker in Afghanistan, said the most common factor behind the civilian deaths has been an American reliance on incomplete information to decide on targets.

"Smart bombs are only as smart as people on the ground," Ms. Ruzicka said. "Before you bomb, you should be 100 percent certain of who you are bombing."

The most recent errant strike, around the village of Kakrak in Oruzgan Province, appears to have resulted from a reliance on faulty intelligence and the use of excessive force in trying to kill people that the American pilots believed were enemy fighters.

On July 1, during an operation to hunt Taliban leaders, an American AC-130 gunship attacked four villages around the hamlet of Kakrak. American soldiers later found villagers gathering up the limbs of their neighbors. Local officials counted 54 dead, most of them women and children, and at least 120 wounded.

American pilots fired on Kakrak after Special Operations forces on the ground reported seeing antiaircraft guns firing at the plane, military officials said. According to the villagers, there were two engagement parties that night, and some of the men were firing their guns in celebration, an Afghan tradition. The Americans said their planes had been fired on, but the villagers deny aiming at anything.

American officials have acknowledged that the raid killed innocents, and they have sent a team to the village to investigate.

"I have seen nothing that said the aircraft was fired on," said Brig. Gen. John Rosa Jr., the deputy director of the Joint Staff in Washington. "I don't know that. It could well have been."

But for Afghans, the larger issue is what the Americans were doing there in the first place, and why they attacked the villages with such ferocity. As in past cases, they say the Americans relied on bad information, from an Afghan intelligence official from another tribe, and that they fired their guns before they were sure who they were shooting at.

"The Americans are not from here and they don't know our traditions or our enemies, and who has enemies," said Jan Muhammad, the governor of Oruzgan Province who spent three years in jail under the Taliban. "So they should contact us first and check first."

The raid on July 1 was the sixth since January that the United States had carried out to hunt Taliban leaders in Southern Afghanistan. So far, they have not detained even a single important Taliban leader but have killed more than 80 people.

In Kakrak, five men were arrested. Among the homes hit there was that of Abdul Malik, who fought with Hamid Karzai, now Afghanistan's president, last fall when he launched a local campaign to oust the Taliban. Mr. Malik lost 25 family members.

"Every time they say that they will coordinate more," Mr. Muhammad said. "They killed my people in Oruzgan and they said they would not make a mistake again and that they would contact us first. Then they did it again."

What angered Afghans like Mr. Muhammad, and Westerners working in the area, is what they described as a trigger-happy American approach. No Americans entered the village before the planes opened fire. Once called in, the American AC-130 gunship, which employs heavy-caliber machine guns, and cannons, strafed four villages.

"Two questions remain," said a Western aid official working in southern Afghanistan. "Why they attacked with such force, and what precautionary moves do they take to differentiate between civilians and Al Qaeda and Taliban. They attacked quite a big area, four villages, and you cannot just assume that everyone there is the enemy."

The pattern of striking with maximum force on questionable targets began months before, when American planes attacked an ammunition dump in the village of Niazi Qala, 50 miles south of Kabul, and wiped out the entire village. A United Nations spokeswoman said 52 people died there.

Local Afghans said that Taliban leaders, then in their last days, had moved a large store of ammunition to Niazi Qala, fearing that the American planes would find it if they left it stored in a fort in Gardez, the provincial capital.

The American planes found it anyway, striking Niazi Qala on the night of Dec. 29.

A reporter visiting the village a month after the attack found no sign, apart from the remnants of the ammunition depot, of Al Qaeda or Taliban.

Seven months later, with summer in full bloom, the town stood lifeless. Niazi Qala's six survivors live in a nearby village, among them, Ahmed Gul, a 13-year-old boy with an ill-fitting plastic eye, and his 12-year-old cousin, Lal Muhammad, his torso crisscrossed with scars.

"All the Americans had to do was come here, and they could have seen for themselves that there were no Taliban among us," said Janat Gul, one of the survivors.

An American military official interviewed about Niazi Qala did not deny that civilians were killed there, but he insisted the village had been a base for Taliban and Qaeda fighters. "This compound was in use by Taliban and Al Qaeda senior leadership," he said. The official did not name who those senior officials might have been.

Haji Saifullah, the leader of the Gardez ruling council, said the Americans had relied on faulty intelligence provided by a local warlord, Padsha Khan Zadran. Mr. Zadran, who was then vying to become governor of the area, told the Americans to strike the town in order to eliminate a village that had refused to support him, Mr. Saifullah said.

"The Americans got it completely wrong," Mr. Saifullah said in an interview. "These people were not Al Qaeda. The Americans are listening to the wrong people."

One of the most deadly of the questionable American raids came when Mr. Zadran apparently used his influence with the Americans to call in a strike on his political foes.

On Dec. 20, according to rival Afghan commanders in Gardez, Mr. Zadran ordered fighters manning a checkpoint south of the city to halt a convoy of tribal elders from Khost who were heading to Kabul for the inauguration of the new interim government. They demanded that the elders pressure Mr. Karzai to appoint Mr. Zadran the governor of Paktia Province, Paktika and Khost provinces. The elders, Afghans in Gardez say, refused.

A few hours later, the convoy of elders was hit by a succession of American attacks, killing most of the occupants. The survivors scrambled up a hill, toward the villages of Asmani and Pokharai, and the American planes, circling back, struck both villages, destroying about 20 homes.

Rival warlords in Gardez say Mr. Zadran used his satellite phone to tell the Americans that the convoy was filled with Qaeda fighters.

A few weeks after the strike, two men from a nearby village who were found sifting through the rubble of Asmani for their relatives' belongings said they had buried 42 villagers after the strike. The men were adamant that there had never been any Qaeda or Taliban fugitives there.

"I swear it, I collected all the bodies, and every one was a villager, somebody I knew," said Hajji Khial Khan, one of the men.

A senior American military commander said said both the convoy and the villages were valid military targets, filled with enemy forces.

At Asmani, Akal Khan Kharakhel, one of the men rummaging through the ruins was asked what lesson the Americans might draw from what happened. He did not hesitate.

"The Americans' big mistake was to give satellite telephones to a man who has only one interest, and not the same one as the Americans," Mr. Kharakhel said, referring to Mr. Zadran, the warlord.