The US Marine Corps has opened a special tribunal into the deaths of Afghan civilians last March.
An Afghan report said the US marines used indiscriminate force
As many as 19 Afghan civilians were allegedly killed when marines opened fire in Nangarhar province after their convoy was attacked by a car bomb.
An Afghan inquiry said the US troops opened fire indiscriminately but the marines said they were fired on and the civilians were caught in the crossfire.
The tribunal is to recommend if two officers should face criminal charges.
The fact-finding tribunal is to focus on the actions of Maj Fred C Galvin, the commander of the marine unit, and Capt Vincent J Noble.
The tribunal is to recommend whether or not the two officers should be charged with conspiracy to make a false official statement, dereliction of duty, failure to obey a lawful order and making a false official statement, Associated Press news agency said.
The commander of US marine forces in the Central Command area, which includes Afghanistan, will ultimately decide whether the charges should be filed.
The troops were from a newly-formed unit called the Marine Special Operations Command.
They were travelling on Highway 1 in Nangarhar province, near Jalalabad, on 4 March 2007 when their six-vehicle convoy was rammed with a van full of explosives.
The soldiers said they came under fire after the van exploded, but an inquiry by Afghanistan's Independent Human Rights Commission cited witness reports saying the marines had fired indiscriminately at pedestrians and vehicles in six different locations along a 10 mile (16 km) stretch of road.
In a move controversial within the US military, eight marines were called back to the US and the rest of the unit was removed from Afghanistan.
Also controversially, an army commander apologised in May over the incident.