NATO-led forces are investigating the death of four Marines in eastern Afghanistan after their commanders reportedly rejected requests for artillery fire in a battle with insurgents, the Pentagon said on Wednesday.
Tuesday's incident was "under investigation" and details remained unclear, press secretary Geoff Morrell told a news conference.
A McClatchy newspapers' journalist who witnessed the battle reported that a team of Marine trainers made repeated appeals for air and artillery support after being pinned down by insurgents in the village of Ganjgal in eastern Kunar province.
The U.S. troops had to wait more than an hour for attack helicopters to come to their aid and their appeal for artillery fire was rejected, with commanders citing new rules designed to avoid civilian casualties, the report said.
Morrell said the helicopters were not hampered by any restrictions on air power but had to travel a long distance to reach the Marines at the remote location near the Pakistan border.
"I think that it did take some time for close air support to arrive in this case, but this is not a result of more restrictive conditions in which it can be used," he said.
"It was the result, as is often the case in Afghanistan, of the fact that there are great distances often between bases where such assets are located and where our troops are out operating."
Morrell could not confirm whether appeals for artillery fire were denied by commanders.
According to the McClatchy report by Jonathan Landay, the U.S. advisors assisting Afghan forces had been assured before the operation that "air cover would be five minutes away."
The incident comes after the top commander of U.S. and NATO forces in Afghanistan, General Stanley McChrystal, issued new restrictions on the use of military force and air raids in a bid to prevent civilian deaths.
McChrystal has warned that civilian casualties caused by the NATO-led force risk alienating the Afghan population and jeopardizing the war effort.
But the general and other top military officials have insisted air support and fire power would not be restricted when U.S. troops were under direct threat.
Bombing runs by coalition forces have declined sharply since McChrystal took over command in June, U.S.A Today reported on Wednesday, citing military statistics.
Tuesday's firefight in eastern Afghanistan involved a 13-member team of U.S. Marine and Army trainers assigned to the Afghan national army, the report said.
Eight Afghan soldiers and police and an Afghan interpreter also died in the battle, which lasted for hours with insurgents unleashing a barrage of gunfire and rockets from mountain positions, the report said.
When an Afghan soldier demanded helicopter gunships, U.S. Major Kevin Williams replied through an interpreter: "We are pinned down. We are running low on ammo. We have no air. We've lost today."
The Americans were assisting Afghan forces in an operation that called for Afghans searching the hamlet for weapons and then meeting village elders to plan police patrols.
But U.S. officers suspected insurgents were tipped off about the operation beforehand, as the coalition and Afghan forces were ambushed as they approached the outskirts of the hamlet at dawn, the report said.