The head of American and NATO forces in Afghanistan has recalled all Western military advisers from government ministries after two high-ranking U.S. military officers were shot dead.
Officials say the gunman has not been identified, but a manhunt is under way.
Reporting from Kabul, NPR's Quil Lawrence says the officers died inside a high-security area of the Afghan Interior Ministry building after an individual turned his weapon on them.
U.S. Army Gen. John Allen, the commander of NATO forces, called the perpetrator a coward whose actions "will not go unanswered." Allen said he recalled all NATO personnel from the ministries "for obvious force protection reasons."
Although there has been no official statement that the shooter was an Afghan, The New York Times reports that in an e-mail sent to Western officials from NATO, the incident was described as "green on blue," the military term used "when Afghan security forces turn their weapons on their Western military allies."
NATO forces have advisers embedded in many Afghan ministries, both as trainers and to help manage the transition to Afghan control. Lawrence tells weekends on All Things Considered host Guy Raz that the attacks come in the midst of negotiations of the enduring U.S. and NATO role in Afghanistan.
"The U.S. and Afghanistan are in the process of negotiating a strategic partnership agreement that would determine how many troops are going to stay here in an advisory role past 2014," he said. "And this tension is certainly going to put a lot of pressure on those negotiations."
Secretary of Defense Leon Panetta supports the decision to recall the advisers, according to a statement from the Pentagon. The statement also said that Afghan Defense Minister Rahim Wardak called Panetta and expressed his condolences for the incident.
Panetta urged the Afghan government to take decisive action to protect coalition forces and curtail the violence in Afghanistan.
The Associated Press reports that the Taliban has claimed responsibility for the attack, saying it was retaliation for the burning of the Muslim holy book at a U.S. military base.
Earlier this week, NATO announced that U.S. soldiers had burned several copies of the Quran, reportedly by accident. This sparked several days of riots and violent protests. At least 28 people have been killed, including two U.S. soldiers, and hundreds wounded.