Amrullah Saleh, the head of Afghanistan's intelligence service, said three militants stormed the Serena Hotel on Monday evening. A guard shot and killed one attacker, which triggered his suicide vest.
A second attacker blew himself up near the hotel's entrance, and the third attacker made it inside the hotel and shot his way through the lobby and toward the gym, Saleh said.
The third attacker was eventually apprehended and arrested.
Saleh showed a picture taken from the hotel's security cameras showing a man in a police uniform and holding a gun inside the hotel's lobby, apparently the third attacker.
A senior Taliban commander, who says he's in charge of militant operations in Kabul, told CBS News after the hotel incident that it was just the beginning of a series of planned attacks against Western interests in the Afghan capital.
Qari Muhammad Talha spoke by phone to CBS News' Sami Yousafzai from an undisclosed location, and said the Monday attack had been carried out by a group of four militants, who had initially planned to hit the hotel last week. He said the plans were delayed due to a "small communication gap" at the last minute.
Talha promised a coming series of attacks against Western missions, hotels, bars and brothels run by Chinese nationals. He warned Afghans working in any such businesses "would get killed if they go to their jobs".
"The Karzai regime has totally failed, and within six months, due to our attacks, 50 percent of embassies and foreign missions will leave Kabul," Talha boldly predicted.
Militants with suicide vests, grenades and AK-47 rifles attacked the luxury hotel on Monday in the most brazen attack yet on Western civilians in Kabul.
U.N. Secretary General Ban Ki-moon said the Norwegian foreign minister, who was not hurt, was the target of the assault, which came as the Norwegian embassy was holding a meeting at the Serena Hotel. Two U.S. State Department officials said at least one American was among the dead. A Norwegian reporter also died.
"They do not care whoever, whatever. This is really a serious crime against humanity," Ban told several reporters at U.N. headquarters in New York.
Norway in past years has been singled out at least twice among nations al Qaeda has said should be targeted because of its participation in the NATO-led coalition in Afghanistan and a previous deployment in Iraq. However, there have not been any recent threats that authorities took seriously.
It was the first direct assault on a hotel in Kabul since the fall of the Taliban in 2001. The assailants appeared to concentrate on the hotel's gym and spa, where foreigners relax and work out. An American inside said she saw a dead body and pools of blood in the lobby.