Two Americans were injured when a vehicle from the U.S. consulate came under attack Wednesday in western Afghanistan, officials said.
The U.S. Embassy in Afghanistan said in a statement that the Americans were "lightly injured" and are being treated at a Spanish hospital in the city of Herat.
"The U.S. government is working closely with Afghan authorities to investigate the incident and bring the perpetrators to justice," it added.
The convoy had come under mortar and machine gun fire as it was travelling on an airport roads towards the city, according to Gen. Samiullah Qatra, provincial police chief of Herat.
Qatra added that police are searching for the attackers.
There was no immediate claim of responsibility for the attack, which came a day after President Barack Obama announced a plan to maintain 9,800 military personnel in Afghanistan after the American combat mission ends there this year, pledging that he will bring the war there to "a responsible end."
Last week, gunmen opened fire on India's consulate in Herat but no staffers were hurt.