PESHAWAR, Pakistan - Out of the chaos, smoke and rubble left by nearly two weeks of intense American bombardment, a wrenching question emerges: How many innocents are dead?

The Taliban, Afghanistan's Islamic rulers, claim up to 400 people _ mostly civilians _ have been killed in airstrikes that have pounded the country for 13 days and nights, hitting targets in and around nearly all its major population centers.

The Pentagon calls the Taliban figures self-serving and exaggerated _ but acknowledges that in an air war, civilian casualties are almost impossible to avoid, whatever care is taken to prevent civilians from being hurt and killed.

The United States hasn't given a number of how many civilians it believed have died. The Pentagon acknowledged that one of its missiles went astray and hit homes in Kabul, saying there were reports up to four people were killed. It also confirmed four workers for a U.N.-funded agency were killed, though whether by a missile or by errant Taliban anti-aircraft fire was unclear.

As frightened refugees pour across the borders of Pakistan, they are providing firsthand accounts of deaths they have witnessed _ often agonizingly close to home.

At the Chaman border post, closest to the Afghan city of Kandahar, the Taliban's home base, 55-year-old Haji Noor Mohammed had tears pouring down his bearded face as he crossed into Pakistan.

"They killed my whole family," he said. "My wife and four children were burned to death when a bomb hit my house.... May Allah avenge their deaths."

Compelling as such accounts are, they have been too scattered to provide a comprehensive picture of what is happening across Afghanistan. In many cases, though, groups of refugees arriving on the same day have painted a consistent and credible picture of airstrikes hitting a particular neighborhood _ often one lying somewhere near a military target, such as an airport.

Afghanistan's near-total isolation makes independent investigation of casualty claims almost impossible. All foreigners were ordered out before the airstrikes began.

Taliban authorities did bring one group of foreign journalists into the country last Sunday to visit Karam, a remote village outside the eastern city of Jalalabad. Taliban officials said at least 200 civilians had died in an airstrike there four days earlier.

The village was nearly flattened; giant craters were visible. Fresh graves, bloodied bedding and animal carcasses could be seen, and a nearby hospital was treating dozens of injured. But there was still no way to pin down the precise numbers of dead.

Sophisticated technology isn't enough to prevent deaths from occurring on the ground.

Last Saturday, the Pentagon acknowledged a "smart bomb" had missed its target by a mile, hitting a residential neighborhood instead of the Kabul airport. It said the target coordinate had been entered incorrectly into the guided bomb's satellite navigation system.

Even when it's clear that a mistake has been made, the consequences are difficult to assess. The Taliban said four people were killed on the ground in the "smart bomb" incident; an Associated Press correspondent who went to the scene could confirm only one death.

In some instances, a third party is able to provide official confirmation about deaths or injuries. The United Nations provided the first outside confirmation of civilian casualties _ four guards who died when the office of their U.N.-funded mine-clearing agency was hit on Oct. 8, the second night of bombardment.

The intended target of that stray strike isn't known; the building wasn't far from a transmission tower, and there was a munitions dump in the area as well. The casualty count has led to some tense exchanges. On Thursday, a Taliban spokesman, Abdul Hai Muttmain, told the Qatar-based satellite TV channel Al-Jazeera that more than 600 people had been killed in airstrikes, and thousands wounded.

In Washington, Defense Secretary Donald H. Rumsfeld strongly disputed that.

"The numbers the Taliban has been floating out in the media are, we are certain, false," he said, adding that "the information from the ground tends to be self-serving."

The United States has expressed regret over civilian casualties, insisting that American forces are targeting only Osama bin Laden and his Taliban allies. Washington holds bin Laden and his al-Qaida network responsible for the Sept. 11 attacks on the World Trade Center and the Pentagon.

Throughout the Muslim world, however, the civilian casualties, whatever their true numbers, have dramatically hardened resentment against the United States. Al-Jazeera, for example, airs graphic nightly footage of wailing, wounded children and bloody corpses half-buried in rubble.

At an anti-U.S., pro-Taliban rally in Peshawar on Friday, civilian deaths were the main theme of fiery speeches to a crowd of several thousand people.

"The United States is committing atrocities against civilians," said the speaker, Qazi Hussein Ahmad. "Jihad, jihad!" the crowd roared in response. "Crush America!"