The U.S. military says American Marines accused of killing 19 Afghan civilians while responding to an ambush last year acted in accordance with military rules.

Military officials said Friday the commander of Marine Corps forces (Central Command) decided not to bring criminal charges against officers involved in the March 2007 operation.

Officials said Lieutenant General Samuel Helland determined the officers acted "appropriately" after coming under attack in Afghanistan's eastern Nangarhar province.

The military has called the incident a "complex attack," in which a suicide car bomber rammed a U.S. convoy before other militants opened fire, sparking a gun battle.

Afghan witnesses and police have said U.S. troops fired on civilians, killing up to 19 people and wounding several others. U.S. officials have said it is not clear whether the civilians were killed by American troops or the militants.

Some information for this report was provided by AFP, AP and Reuters.