KABUL, Afghanistan -- A firefight broke out between U.S. forces and their Afghan army allies in eastern Afghanistan Sunday, killing two Americans and three Afghan soldiers and pushing the number of U.S. troops killed in the long-running war 2,000.
The fighting started Saturday when what is believed to have been a mortar fired by insurgents struck a checkpoint set up by U.S. forces in Wardak province, said Shahidullah Shahid, a provincial government spokesman. He said the Americans thought they were under attack from a nearby Afghan army checkpoint and fired on it, prompting the Afghan soldiers to return fire.
The Afghan Defense Ministry said the gunbattle was the result of a "misunderstanding" between international forces and Afghan soldiers manning a checkpoint in the Sayd Abad district.
NATO's International Security Assistance Force, commonly referred to as ISAF, provided a different account.
"After a short conversation took place between (Afghan army) and ISAF personnel firing occurred which resulted in the fatal wounding of an ISAF soldier and the death of his civilian colleague," the coalition said in a statement. It said the three Afghan soldiers died "in an ensuing exchange of fire."
NATO did not say whether it considered this an "insider" attack on foreign forces by Afghan allies.
There has been rising tide of such attacks in which Afghan soldiers or police assault their international allies. The killings pose one of the greatest threats to NATO's mission in the country, endangering a partnership key to training up Afghan security forces and withdrawing international troops.
While it may be days before it becomes clear who fired on whom first, the incident illustrates how tense relations have become between international troops and their Afghan allies.
Officials on both sides went into damage control mode, arguing that Saturday's violence did not mark a new low in Afghan-U.S. relations and urging patience while investigators tried to figure out exactly what had happened.
The deputy commander of NATO's military force in Afghanistan, British Lt. Gen. Adrian Bradshaw, called a last-minute news conference in Kabul to address the incident, even though he had few details to give.
He said the initial report of an insider attack should be amended to note that the incident "is now understood possibly to have involved insurgent fire," and tried to stress that relations between international troops and their Afghan allies "are very strong and very effective."
A spokesman for the Afghan Defense Ministry, Gen. Zahir Azimi, also sought to downplay the incident.
"In a misunderstanding shooting broke out between Afghan army and ISAF forces. As a result of the shooting, three army soldiers were killed, three other soldiers were wounded and number of ISAF forces were killed and wounded," Azimi said in a statement.
One U.S. official confirmed that the service member killed was American, while another confirmed that the civilian was also American. The officials spoke on condition of anonymity because the nationality of the dead had not yet been formally announced.
The number of American military dead reflects an Associated Press count of those members of the armed services killed inside Afghanistan since the U.S.-led invasion on Oct. 7, 2001.
In the south meanwhile, three Afghan police officers were killed when insurgents attacked a checkpoint in Helmand province Sunday morning, provincial police spokesman Fareed Ahmad said.