A US citizen was killed in an attack on a hotel in Kabul used as a CIA office on Sunday. The attack was carried out by an Afghan employee who was also killed. Officials are still investigating what happened in an area with restricted access even for Afghan security forces. The Ariana hotel is just a few blocks away from the presidential palace and the US Embassy, in a heavily guarded military and diplomatic enclave almost entirely inaccessible to casual visitors. Kabul police chief, Ayub Salangi, said there had been an incident at the Ariana hotel, which he described as an "office" for the US government's Central Intelligence Agency. He had no further information. Afghan security forces have only limited access to the area. The CIA and the US Embassy in Kabul declined to comment. But a US official, who declined to be named because of the sensitivity of the situation, confirmed an attack had been made against a US facility in Kabul. Access to the hotel has been restricted at least since the fall of the Taliban government in late 2001. Perhaps because of its proximity to the presidential palace, it was used by ruling regimes for years before that.