A squad of up to eight Taliban suicide bombers and gunmen laid siege to a landmark hotel overlooking the Afghan capital late Tuesday, sparking an hours-long firefight that ended only when NATO helicopters shot dead several insurgents who had commandeered the building’s roof.

The audacious and heavily armed assault, for which a Taliban spokesman quickly asserted responsibility, shattered any sense of security in the sprawling capital. The attack, which left at least 11 dead and 14 wounded among civilians and security forces, comes as Afghanistan prepares to begin a transition from international to full domestic control of defense, security and civilian governance.

The insurgents targeted one of Kabul’s best-known and best-protected buildings, the historic Intercontinental Hotel, on a hilltop in the city’s west. It was unclear exactly how they managed to reach the site, but at least one police official said early Wednesday that the assailants had been wearing police uniforms.

Police officials said the attackers exploded a vehicle at the site’s entrance, then sent a team of bombers and gunmen inside the hotel, where a wedding was underway and a meeting of the nation’s provincial governors was being prepared.

The Taliban spokesman, in a chilling statement early Wednesday, said the attackers had called during the siege to report killing at least 50 “foreign and local enemies” inside the hotel. The statement, sent to various news outlets, said some attackers had reached all five floors and had gone door to door, pulling guests out of their rooms and shooting them.

However, an official from the Interior Ministry, Samoonyar Zaman, told reporters that all 60 to 70 guests were safe in their rooms. Officials said that some provincial governors and their staff members had been in the hotel, preparing for a two-day conference on the security transition, but that the governors may have left.

Latifullah Mashal, the spokesman of the Afghan National Directorate for Security, said eight suicide attackers were involved and all had either blown themselves up or been killed by Afghan or coalition forces, the Associated Press reported Wednesday.

The 11 civilians killed included a judge from an unnamed province, five hotel workers and three Afghan policemen, Mashal said. He said no foreigners were killed, but two foreigners were among 14 people wounded in the attack. He did not disclose their nationalities.

The assault was apparently quelled about 2 a.m. when two NATO attack helicopters shot down three insurgents still fighting from the hotel roof. Jason Waggoner, a spokesman for the U.S-led coalition, said the helicopters were called in after several loud explosions were heard from the hotel. He said that the helicopter crews killed three gunmen and that Afghan security forces reached the roof from below and killed the remaining insurgents. An Interior Ministry spokesman, Sediq Sediqqi, then declared that all the attackers were dead.

This is the second bombing in Kabul this year of a hotel frequented by foreigners, after an attack in February on the Safi Landmark hotel. In January 2008, an insurgent commando squad invaded the luxury Serena Hotel in downtown Kabul, killing seven people, including several foreigners.

This time, the target was a much older and more established hotel that had experienced vertiginous swings of fortune during Afghanistan’s four decades of conflict, occupation and rebirth.

The Intercontinental, built in the 1960s, was once a fashionable institution with a grand piano in the lobby and a wine cellar in the basement. It was partly abandoned during the Soviet occupation of the 1980s and badly damaged by multiple rocket attacks during the urban civil war that followed.

After the Taliban took power in 1996, the hotel was nearly deserted, with armed Taliban fighters in the lobby, cold water delivered in buckets to a handful of guests, and waiters serving spaghetti prepared in enormous empty kitchens. Once the Taliban was ousted in 2001, the hotel was gradually refurbished and became a popular site for social events, business conventions and political conclaves.

As the battle continued into the night, police blocked all roads leading to the hotel, which is perched on a steep slope covered with vegetation. Electricity was cut off in the immediate area, leaving the scene pitch dark as heavy gunfire echoed. Live Afghan television news coverage showed a dark scene punctuated by bright lights and sirens from police vehicles.

One guest told a local reporter he had been eating dinner with his family when he heard a loud explosion and gunfire. He then jumped from a first-floor window with his family and ran away.

There was heavy security throughout the capital Tuesday because of several major events: the governors’ conference, a meeting of international observers and a meeting of Afghan, Pakistani and U.S. officials. But the insurgents, who were extremely well prepared, managed to avoid the constant traffic stops and transport a considerable arsenal into the hotel, raising what were likely to be major questions about the ability of Afghan forces to protect the capital of 4 million.

In recent weeks, Taliban insurgents and suicide bombers have staged several attacks in Kabul after a long lull. Three suicide bombers tried to attack a local police facility this month, dying in the attempt. Another group invaded the headquarters of the Defense Ministry in April in an assault that left two soldiers dead.

There has also been a series of especially audacious or high-profile insurgent attacks outside the capital, including the beheading of a provincial leader, the assassination of a prominent police general and the suicide bombing of a rural hospital. Officials said the insurgents have been trying to undermine the planned transition from NATO to Afghan control of national defense.