Pentagon Sources: Civilians likely killed without provocation

WASHINGTON (CNN) -- An ongoing military investigation supports allegations that U.S. Marines in November killed 24 innocent Iraqi civilians without being provoked, senior Pentagon sources said Friday.

Charges, including murder, could soon be filed against Marines allegedly involved, the sources said.

The killings reportedly occurred while troops from the 3rd Battalion, 1st Marines were searching for insurgents who planted a roadside bomb that killed a member of the unit.

The Marines originally had reported that 15 civilians were killed by a roadside bomb in Haditha, a city along the Euphrates River in western Iraq. The Marines later suggested the civilians may have been caught in a firefight.

However, photographs being reviewed by investigators "are inconsistent with how the Marines claim the Iraqis died," according to a military source familiar with the investigation.