In the aftermath of one of the deadliest attacks since the start of the U.S.-led war in Afghanistan, new details have emerged about the fierce weekend firefight in Nuristan province.
At times, the Taliban breached U.S. defenses during the fighting, and one U.S. official said "everything in the area that was available," including helicopters, fighter jets and drones were called in to repel the attack.
Initial reports said that eight Americans have died in the attack and 24 were wounded. Two more Americans were killed by roadside bombs on Sunday, bringing the death toll for Americans in Afghanistan to at least 17 so far for the month of October, already making it one of the deadliest months of the war.
The bloody weekend increased pressure on the Obama administration during its ongoing review of military strategy there.
ABC News' Chris Cuomo, reporting from Jalalabad on "Good Morning America" Monday, said the situation in Nuristan was generally calm after three days of intense fighting near a pair of remote U.S. outposts in the Kamdesh district, just 10 miles from the Pakistan border. Military officials say more than 300 Taliban fighters descended on the U.S. compound which was just days away from being closed.
Revealing new details of the weekend attack, a senior military official told ABC News that a fire swept toward the compound during the fight, consuming "building after building, structure after structure." The fire forced U.S. troops back into one compound, meaning they were actually hunkered down at one point as the fighters sporadically gained access to the camp itself.
A senior officer told ABC News that initial reports indicated that the fighting spilled into the compound for a time. "They moved in and out," the source said.
Besides attacking from the mosque and the village, insurgents also held high ground and poured "significant and effective fire from elevated areas. The area they fired into was a valley," the senior military official said.
The insurgents reportedly launched their attacks from a nearby mosque where they had "significant and effective fire from elevated areas." The U.S. compounds are located in a valley. Military sources say the insurgents used a 50 caliber, heavy machine gun to rake the base.
U.S. forces called in air support right away, but rugged terrain and the raging fires restricted visibility for the pilots, "both in being able to come into the area and in identifying targets," a military official told ABC News.
ABC News correspondent Karen Russo flew into the battle zone on a Medevac helicopter and described cork-screwing into the landing zone to a valley at the bottom of steep mountains. There was little visibility because of the smoke and the area smelled of burned out pine trees, something one soldier described as "death and hell."
The military declined to identify the unit that was under attack until families of the soldiers were notified.
Attack Puts Pressure on Obama Administration
Taliban fighters were "almost certainly" backed by Hezb-e-Islami, which is run by militant commander Gulbuddin Hekmatyar, an Islamist group that is independent of the Taliban. "It would have had to be complicit in the attack."
Afghan sources told ABC News that the attackers included elements from Pakistan who had been ousted from the provinces of Bajaur and Swat by a Pakistani offensive.
In addition to the U.S. casualties, at least six Afghan soldiers were killed and several of their vehicles were captured. The Taliban are claiming that 25 police – including a district police chief – have surrendered.
The fighting took place near Wanat where a U.S. outpost was nearly overrun by a Taliban attack about a year ago. Nine U.S. soldiers were killed in that attack, which was up until then the bloodiest battle of the war for American soldiers.
The U.S. outpost was reportedly just days from being closed as part of U.S. Gen. Stanley McChrystal's strategy to shift troops away from remote locations that are difficult to defend and move them to populated areas to focus on protecting Afghan civilians.
McChrystal has also said more resources are needed for that strategy to succeed, asking Obama to send 40,000 more troops to reinforce the 60,000 already deployed to Afghanistan.
Some of Obama's advisers oppose a major troop increase and have suggested the U.S. focus on going after al-Qaeda figures across the border in Pakistan. The president and his National Security Council will convene a second meeting on Afghanistan strategy this week.
Among the questions at the heart of the strategy discussions is whether "nation building" in Afghanistan – including achieving political stability throughout the country – makes sense if it's not clear that the nation can be built.
Recent Afghan national elections were not as successful as many Obama administration officials had hoped, with widespread reports of fraud and corruption. The results have caused some administration officials to suggest a narrower focus for U.S. strategy may be needed. An audit of disputed Afghan ballots is expected to begin today with final results announced as early as Friday.
In an interview with ABC News' Diane Sawyer on "Good Morning America" today, former deputy head of the U.N. Mission in Afghanistan Peter Galbraith characterized the Afghan election as "massive fraud" that was "preventable" by U.N. watchdogs.
The U.N. "did not exercise its responsibility," he said. Galbraith was recently fired from his post. He was the highest American member of the U.N. mission.
When asked if he had reservations about his outspokenness in the wake of his firing, Galbraith told Sawyer, "No, no second thoughts."
Galbraith has also warned against sending more U.S. troops to Afghanistan saying "in the absence of having a credible Afghan partner – that is to say a government that enjoys the support of the people and is accepted by the people" – relying on U.S. forces to achieve peace and stability there is a difficult prospect.
"It makes no sense to ramp up [troops]," he said. "But on the other hand, we cannot afford to pull out. …The only way this works is if we make a transition to the Afghans, and that requires an effective Afghan government, and that requires a credible election."
ABC News' Martha Raddatz and Jim Sciutto contributed to this report