KABUL, Afghanistan -- American officials Wednesday blamed the bold attack on the U.S. Embassy on a Pakistan-based group allied with the Taliban, acknowledging that the assault brought a propaganda victory for the insurgents even as they played down its military significance.
The attack underscored holes in Afghan security: Six fighters with heavy weapons took over an unfinished high-rise that authorities knew was a perfect roost for an attack on the embassy and NATO headquarters about 300 yards away. They then held out against a 20-hour barrage by hundreds of Afghan and foreign forces.
It appeared likely that either weaponry had been stored in the 12-story building ahead of time or that some insurgents had entered in advance with a supply of guns and ammunition.
By the time the fighting ended at 9:30 a.m. Wednesday, the insurgents had killed 16 Afghans -- five police officers and 11 civilians, more than half of them children. Six or seven rockets hit inside the embassy compound, but no embassy or NATO staff members were hurt. All 11 attackers -- including four suicide bombers who targeted police buildings elsewhere in the city -- were killed, authorities said.
Police could be seen clapping their hands in celebration on the roof of the high-rise. Others carried the mangled bodies of insurgents down flights of rough concrete stairs and piled them into the back of a waiting ambulance.
Although the Taliban claimed responsibility for Tuesday's assault, U.S. and Afghan officials said the Haqqani network likely carried it out on their behalf. The Haqqanis have emerged as one of the biggest threats to Afghanistan's stability, working from lawless areas across the border in Pakistan's tribal region.
Nearly all Taliban attacks in and around the Afghan capital have been executed by the Haqqanis, who are also allied with al-Qaida. The Haqqani network was also blamed for a weekend truck bombing in eastern Wardak Province that wounded 77 U.S. soldiers.
"It's tough when you're trying to fight an insurgency that has a lot of support outside the national borders," U.S. ambassador Ryan Crocker said. "It's complicated, it's difficult but clearly for a long-term solution those safe havens have to be reduced."
U.S. officials have been pressing Pakistan to go after Haqqani militants. But relations with Islamabad have not been good, particularly after the U.S. raid in May that killed al-Qaida leader Osama bin Laden.
Crocker said Tuesday's attack would not affect the transfer of security responsibilities from the U.S.-led military coalition to the Afghan security forces. Foreign forces are to completely withdraw combat troops by the end of 2014.
U.S. Marine Corps Gen. John Allen, the top commander of U.S. and NATO forces in Afghanistan, said the assault did not mean that Afghan security forces weren't doing their job, arguing that potential attacks are thwarted in Kabul nearly every day. However, he did allow that the violent standoff gave the Taliban the headlines they wanted.
"I'll grant that they did get an IO (Information Operations) win," Allen told reporters in the capital.
NATO's senior civilian representative, Simon Gass, called the attack "extremely frightening even for the citizens of Kabul."
Both men argued that the insurgents depend on these spectacular attacks because they can't take and hold ground.
"This really is not a very big deal," Crocker said. "If that's the best they can do, you know, I think it's actually a statement of their weakness."
But in Kabul, the fear expressed by some residents showed the effectiveness of the current militant campaign. This week's attack was the third major insurgent assault in the capital since late June.
Ghulam Sadeq, 36, who works in a government office, said he doesn't trust the government or the security forces to keep him safe.
"It's true that the security forces were able to defeat attackers and prevent more casualties, but why couldn't they keep them from entering the city? Basically they are unable to stop them, or the insurgents have people helping them," Sadeq said. "There are so many Taliban fighters among the police and army ranks. They can very easily implement plans and launch attacks."
This fear and uncertainty is what analysts say the insurgents are after.
"The Taliban themselves would admit that they are militarily weak in places like Kabul, but their ability to penetrate a place that is the height of security like Kabul is, for them, a win," said Candace Rondeaux, an Afghanistan analyst with International Crisis Group. An attack like this shows that they can get past checkpoints, coordinate planning and pull on connections within the city, Rondeaux said.
There were six police officers assigned to guard the building, specifically because officials had recognized it as a potential platform for an assault, said Wahidullah Ahmad, a policeman who was overseeing the scene after the attack. He said he did not know if any of those guards were among those killed.
Authorities released new details Wednesday about how the attack unfolded.
At about 1:30 p.m. Tuesday, police manning a checkpoint at a traffic circle stopped a minivan filled with what appeared to be women wearing burqas. Suddenly there were explosions, likely either suicide blasts or grenades.
The minivan sped across the circle to the site of the half-built high-rise and quickly set up a firing post from which the militants started to launch rockets and shoot heavy weaponry toward the U.S. Embassy and NATO forces headquarters.
U.S. and NATO officials praised the Afghan forces for routing the enemy, but international troops clearly played a major role.
Associated Press photos show foreign forces inside the building throughout the clearing operation, apparently directing Afghan police alongside them and passing information to helicopters overhead.
It fell upon the helicopter gunships to take out three of the last four insurgent holdouts, said Shafiqullah Ibrahim, an Afghan police inspector.
Associated Press writers Patrick Quinn and Rahim Faiez contributed to this report from Kabul.