Twenty-one people were reportedly killed in Afghanistan on Friday after a suicide bomber and at least two gunmen stormed a restaurant popular with foreign dignitaries and staff in the heart of the most protected area of Kabul.

According to early reports, at least two Americans, two Britons, two United Nations officials, and the head of the IMF in Afghanistan were among the dead.

Shortly after the attack, the Taliban took responsibility for the assault saying it retaliation for a recent US/NATO airstrike that claimed the lives of many civilians in the country.

"The target of the attack was a restaurant frequented by high-ranking foreigners," said Taliban spokesman Zabihullah Mujahid an emailed statement. He said his group targeted the targeted the Taverna restaurant, the owner of which was also killed in the attack, because it was a place "where the invaders ... dine with booze and liquor in the plenty."

The statement continued: “The attack was in retaliation to the massacre carried out by foreign invaders 2 days earlier in Parwan province’s Siyah Gerd district, where the enemy airstrikes destroyed up to 10 homes, razed several orchards as well as killing and wounding up to 30 innocent civilians, mostly defenseless women and children.”

The New York Times reports:

Western officials said they were trying to confirm the Taliban’s stated motive for the coordinated attack, which occurred just two days after the airstrike and would have required extensive planning. A suicide bomber had cleared a path for two gunmen who stormed in and fired on diners, the police said.

Westerners who died in Friday’s attack came from America, Canada, Russia, Lebanon and other countries, and included the head of the International Monetary Fund in Afghanistan and the head of political affairs at the United Nations here, both highly regarded officials who had spent years in the country. Two Americans working at the American University in Afghanistan were also killed in the attack, the university said in a statement Saturday.

And the Guardian adds:

Friday's attack began with a bomb blast that shook the Wazir Akbar Khan neighbourhood shortly after 7pm, as one attacker detonated his explosives at the restaurant's front gate.

It was followed by more than two hours of sporadic gunfire, as Afghan commandos besieged two other attackers. One of the survivors, Suleiman, who worked as a cook at the restaurant, said he escaped from the gunmen after hearing the explosion outside. "I went to the roof and stayed with my back to the chimney for two or three hours. Later Afghan police came and took me out," he said.

It was the deadliest day for the UN in Afghanistan in nearly three years. In April 2011 a rioting mob overran a compound in northern Mazar-e-Sharif city, killing three UN workers and four Nepalese security guards. Eighteen months earlier, in autumn 2009, five UN workers were killed in Kabul when gunmen burst into a guesthouse for the organisation's staff.

The deaths had a far-reaching impact on how the UN and many other international organisations worked in the Afghan capital.

Although there are regular attacks on targets in the Afghan capital, it is rare for attackers to make it through rings of security around the city, elude an extensive intelligence network, and strike at a civilian target around the unofficial "green zone" that houses Nato and US embassy headquarters.

_______________________________