KABUL, Afghanistan – The Taliban claimed responsibility for an attack on a popular restaurant in Kabul on Friday that killed at least 21 people, including three Americans and 11 other foreigners.
U.S. Embassy spokesman Robert Hilton confirmed Sunday that three Americans were among the dead.
Among the dead were two American University of Afghanistan employees.
"We are devastated by the news,” Dr. Michael Smith, president of the university, told NBC News. "The families of the victims are being notified and arrangements for repatriation of the remains are under way."
Also, the United Nations said in a statement that Basra Hassan of the United States was among four of its employees killed in the attack. The others were Nasrin Jamal of Pakistan, Khanjar Wabel Abdallah of Lebanon and Vadim Nazarov of Russia, the U.N. said. Hassan and Jamal worked for the UN Children's Fund.
"I extend my deepest condolences to the families," said Secretary-General Ban Ki-Moon.
"On many occasions, I have condemned in the strongest possible terms the reckless terrorist attacks against civilians. This is totally unacceptable and this is a violation of international humanitarian law," he added.
International Monetary Fund chief Christine Lagarde said in a statement that Wabel Abdallah, 60, the fund’s resident representative in Afghanistan, was also slain.
Secretary-General Ban Ki-moon condemned the brutal attack.
Sediq Seddiqi, the spokesman for Afghanistan's Ministry of Interior, told NBC News on Saturday that the death toll included 13 foreigners and eight Afghans. The foreigners included Germans, Canadians, Russians and Lebanese. He said they included diplomats, but he would not give any further details.
There were conflicting accounts of the attack, but Reuters and The Associated Press quoted unnamed security officials as saying one attacker detonated a bomb and two others then fired on customers and employees in the Lebanese restaurant. The other two were killed by security guards, according to the reports.
The White House and U.S. State Department both decried the attack on Saturday.
"With this despicable, targeted attack on innocent civilians, terrorists continue to demonstrate blatant disregard for life and for the peaceful, prosperous future Afghans want and are working so hard to achieve," State Department spokeswoman Jen Psaki said in a statement. The department previously confirmed that no staff at the U.S. Embassy in Afghanistan were killed or injured in the attack.
The restaurant is in the Wazir Akbar Khan district, which houses many foreign embassies and restaurants that cater to expatriates.
In a statement taking responsibility for the attack, the Taliban said they had targeted "foreign invaders ... having their dinner."
“In this attack we have used very heavy explosives which caused heavy losses to the enemy. According to our initial information, which we received, in this attack we attacked senior officials from the German military and government.”
The Taliban often exaggerates death tolls and embellishes other details in the wake of attacks.
On Saturday, Taliban spokesman Zabihullah Mujahid issued a statement saying that the attack was in response to a recent NATO airstrike in Parwan that caused civilian casualties.
The attack came at a difficult moment for Afghanistan as most foreign forces prepare to leave the country this year after more than a decade of war and almost daily attacks.
Security remains a major concern as Afghanistan and the United States struggle to agree on a key bilateral security pact, raising the prospect that Washington may yet pull out all of its troops this year unless differences are ironed out.
NBC News' Associate Producer Catherine Chomiak and Reuters contributed to this report.