Isaf's Major Tim James: "The Afghan national security forces have responded incredibly well"
Nato helicopters were called in to kill three militants to end a five-hour clash by suicide bombers and gunmen on a hotel in the Afghan capital, Kabul.
The attack on the Intercontinental Hotel, frequented by Westerners, left six more attackers, two police and 11 civilians, including a Spaniard dead.
A security official said the militants may have exploited renovation work to gain access to the high-security hotel.
A Taliban spokesman said the insurgent group had carried out the attack.
However, interior and defence ministry officials told the BBC it bore the hallmarks of the Haqqani network, a group closely allied to the Taliban but which operates independently.
President Hamid Karzai condemned the attack, saying that the insurgents enjoyed spilling innocent blood but that such incidents would not hinder the process of transition of responsibility for security from Nato-led to Afghan security forces.
'Panic'
Smoke and flames could be seen coming from the hotel as the sun rose over Kabul.
Afghan security officials said at least nine militants had stormed the building, and all had been killed.
As well as at least 11 dead civilians and two police, at least eight people were wounded including two New Zealand members of Isaf special forces who were "moderately" injured.
The attack began while many guests were in the dining room late on Tuesday.
Once again there are questions about the effectiveness of Afghan security forces. The fact that a Nato attack helicopter was required to kill gunmen firing from the hotel roof also reinforces this narrative that the Afghan police and army are incapable of operating effectively alone.
A much more detailed analysis of the operation will be required to draw the full lessons.
Beyond the immediate psychological impact of the attack, a curious game of signals is being played here.
Nato is maintaining the military pressure on the Taliban, killing large numbers of middle-ranking commanders, in an effort to persuade the top leadership that negotiations are the only answer. The Taliban, too, are mounting operations like this one to underline that they remain far from defeated and their reach extends to show-case targets in the Afghan capital itself.
Afghan officials told the BBC that one suicide bomber had blown himself up at the front of the hotel and another on the second floor.
Witnesses said panic broke out as guests, including a wedding party, fled for safety.
Afghan troops and police sealed off the building and cut the power, as security forces were using night-vision equipment.
Intense gunfire was heard coming from the hotel and some explosions could be heard up to 5km away, said the BBC's Bilal Sarwary in Kabul.
Afghan police said one militant was shot dead as security forces fought their way through.
Three attackers managed to reach the roof and Afghan officials then asked the Nato-led International Security Assistance Force (Isaf) for assistance, security sources told the BBC.
Isaf spokesman Major Tim James said those killed on the roof by Nato helicopters appeared to have been wearing suicide vests.
"We've had reports that there were a number of explosions caused either by the insurgents detonating themselves or the engagement by the helicopter causing [suicide vests] to explode," he told AFP news agency.
Security conference
Kabul police chief Gen Ayub Salangi said that one of the attackers managed to survive the assault by hiding in a hotel room.
He detonated his explosive vest at around 0700 local time (0230 GMT), after the fighting was thought to have ended, killing two policemen and a Spanish guest, and injuring three others, the police chief said.
The Spaniard had tried to return to his room, against the advice of security forces, he added.
Spain's foreign ministry later confirmed that a Spanish citizen had died, saying that he was an airline pilot.
An Afghan official said the attackers had hand-grenades, rocket-propelled grenades and AK-47s.
Gen Salangi said his own armoured land cruiser had been hit more than 30 times, and its windows were broken.
Officials said a meeting of provincial governors taking place at the hotel might have been the target of the attack
The attack also came the night before the start of a conference about the security transition
Correspondents say the Intercontinental, which is not part of the international hotel chain of the same name, is one of Kabul's most heavily guarded hotels
But a security ministry official told the BBC that the militants could have exploited a loophole in security caused by renovation work.
"The insurgents are using every means to infiltrate into tight security areas. They might have camouflaged themselves as labourers, as technicians or whatever."
The US state department condemned the attack, saying it demonstrated "the terrorists' complete disregard for human life".
Kabul has been relatively stable in recent months, although violence has increased across the country since the killing of Osama Bin Laden in Pakistan on 2 May, and the start of the Taliban's "spring offensive".
In January 2008, militants stormed the capital's most popular luxury hotel, the Serena, and killed eight people, including an American, a Norwegian and a Philippine woman.