WASHINGTON (CNN) -- Security contractor Blackwater said any guards who acted improperly in a deadly 2007 shooting in Baghdad should be held accountable, but believes its team acted in self-defense, a company spokeswoman said.
A woman walks past a burned car in September after an incident involving Blackwater security guards.
Officials familiar with the case said Sunday that six Blackwater contractors have been told they face possible charges in the September 2007 shootings in Baghdad's Nusoor Square.
All six received "target letters" from the Justice Department, which has convened a grand jury to hear evidence in the case, the officials told CNN.
No final decisions have been made, but target letters often signal that criminal charges are in the works.
Iraqi authorities have accused Blackwater guards of killing 17 civilians and wounding nearly 30 in the shootings. But Blackwater has repeatedly said its guards were acting " in response to a hostile threat," company spokeswoman Anne Tyrrell said in a written statement late Sunday.
"Since the September 16, 2007 incident, we have said that, based on statements of company personnel who were directly involved, we believe those involved acted appropriately," Tyrrell said. "If it is determined that an individual acted improperly, Blackwater would support holding that person accountable. But at this stage, without being able to review evidence collected in an ongoing investigation, we will not prejudge the actions of any individual."
The company has given its full cooperation to the grand jury, which was seated in November, Tyrrell said.
Blackwater said its guards were protecting a U.S. diplomatic convoy when they came under fire in Nusoor Square in western Baghdad. But an Iraqi government commission that investigated the shootings accused the guards of firing on civilians indiscriminately. The first U.S. soldiers who arrived on the scene also told investigators they found no evidence the guards were fired upon, sources familiar with the investigation previously told CNN.
An estimated 25,000 private security contractors protect diplomats, reconstruction workers and government officials there.
Security contractors have had immunity from Iraqi law under a provision put into place in the early days of the U.S.-led occupation of Iraq
The Nusoor Square shootings led to angry protests from Iraq, as well as demands that the contractors face trial in Iraqi courts.
CNN Justice Correspondent Kelli Arena contributed to this report.