The Taliban have claimed responsibility for a deadly attack on a café frequented by Western officials in the heart of Kabul. The death toll, now at 21, makes the attack the worst for the United Nations (UN) in Afghanistan in three years, according to The Guardian.

Among the dead are a representative for the International Monetary Fund (IMF), Wabel Abdallah, and Vadim Nazarov, the chief political affairs officers for the UN in Afghanistan. Two Britons and two Americans are also confirmed killed.

The restaurant is located near international offices and was a frequent hangout for expatriates working in Kabul. According to the New York Times, it did not have many of the security measures typically used by official installations, but did have armed guards and steel gates. A suicide bomber detonated a device and “cleared a path” for two gunmen who fired on patrons in the restaurant, says the New York Times.

The Taliban claim the attack was in response to a U.S. air strike two days earlier that killed 14 people, including civilians. Western officials however dispute the Taliban’s statement, saying the attack required more than two days planning to execute.

The Taliban statement also noted the group specifically targeted the café because it was popular among “high-ranking foreigners.” The attack and its targets are unusual for the Taliban, who typically focus on government targets, both of the Afghans and of international bodies. Earlier this month, the Taliban bombed near Camp Eggers, less than a mile from the restaurant attacked Friday.

Three senior Afghan police officers in charge of the district where the restaurant is located have been suspended and are under investigation for negligence. UN officials said they would not adopt a “bunker mentality” following the attack, according to the New York Times.