At least 10 other people were wounded in the assault.
The siege on the Hotel Inter-Continental Kabul ended early this morning after NATO helicopters shot dead the last two attackers on the rooftop of the hotel, which is favored by Westerners and diplomats.
Between six and eight suicide bombers and gunmen stormed the Inter-Continental late on June 28, sparking a gun battle that lasted more than four hours.
An Interior Ministry spokesman, Sediq Sediqqi, said two bombers were killed by hotel guards and the four others either blew themselves up or were killed by Afghan troops or the NATO air strike.
The assault on the hotel lasted nearly five hours and was punctuated by blasts.
After the siege, police surrounded the building and firefighters arrived at the scene. Smoke was seen rising from the hotel but no flames.
The United States condemned the attack.
In a statement, U.S State Department spokeswoman Victoria Nuland said the United States "strongly condemns the attack on the Inter-Continental hotel in Kabul, which once again demonstrates the terrorists' complete disregard for human life."
She said all U.S. Embassy staff were accounted for and that the U.S. special representative for Afghanistan and Pakistan, Marc Grossman, had left Kabul with his delegation hours earlier in the day.
The attack came just hours after U.S., Pakistani, and Afghan officials met in Kabul to discuss prospects for peace talks with Taliban insurgents aimed at ending the nearly decade-long war.
Officials are expected to use a press conference in Kabul to discuss plans for Afghan security forces to take the lead in securing an increasing number of areas of the country between now and 2014, which is when NATO has agreed to move international forces out of combat roles.
Afghans from across the country have arrived in the city to attend the conference. The AP reported that some Afghan provincial governors were staying at the hotel.
"The fact that we are discussing reconciliation in great detail is success and progress, but challenges remain and we are reminded of that on an almost daily basis by violence," Afghan Deputy Foreign Minister Jawed Ludin said at a news conference earlier on June 28. "The important thing is that we act -- and that we act urgently -- and try to do what we can to put an end to violence."
The 1960s-era Inter-Continental was the nation's first international luxury hotel. It has more than 200 rooms.
Major attacks in the Afghan capital are relatively rare, although violence has increased since the May 2 killing of Osama bin Laden in a U.S. raid in Pakistan and the start of the Taliban's annual spring offensive.
On June 18, insurgents wearing Afghan army uniforms stormed a police station near the presidential palace and opened fire on officers, killing nine.
In late May, a suicide bomber wearing an Afghan police uniform infiltrated the main Afghan military hospital, killing six medical students.