Gunmen have killed an American engineer and two Afghans in an area north of Kabul.
Provincial administration spokeswoman Roshan Khalid told VOA, on Tuesday, the attack occurred as the three were traveling from the central Bamiyan province to the capital.
She says no one has been arrested. The Taliban has claimed responsibility for the attack.
On Sunday, a man dressed in an Afghan police uniform killed three foreigner advisers working for NATO in the western Herat province.
In another development, Afghan security officials say they have foiled an insurgent attack on a major international hotel in Kabul.
Officials announced the alleged plot on Tuesday but did not name the hotel.