WASHINGTON (Agencies) -- Federal prosecutors are investigating allegations that employees of Blackwater -- the security firm accused of killing up to 20 Iraqi civilians -- illegally smuggled weapons into Iraq, according to U.S. government sources.

Security operations by North Carolina-based Blackwater USA, which is hired by the U.S. State Department to guard U.S. staff in Iraq, were suspended this week amid concerns by Iraqi and U.S. government officials over the shootings in Baghdad last weekend, CNN reported.
Normal operations resumed Friday, the State Department said.
A U.S. government official said the U.S. attorney's office in Raleigh, North Carolina, is investigating individual Blackwater employees -- not the company -- for illegal weapons deals.
A company source acknowledged to CNN that two Blackwater employees were fired for buying guns with Blackwater money and selling them without the consent or knowledge of the company. It was not clear where the arms were bought and sold.
According to the source, the company caught the two employees and turned them over to the U.S. Bureau of Alcohol, Tobacco and Firearms.
The two, described as having military and law enforcement backgrounds, were fired in 2005, the company source said.
The source asked not to be identified because of the sensitivity of the matter.
The first public hint that an investigation was under way came earlier this week in a statement from State Department Inspector General Howard Krongard when he was accused of blocking fraud investigations in Afghanistan and Iraq.
""In particular, I made one of my best investigators available to help assistant U.S. attorneys in North Carolina in their investigation into alleged smuggling of weapons into Iraq by a contractor,"" Krongard's statement said.
The flow of illegal weapons in Iraq has been a major concern in recent months.
The State Department and Pentagon launched their own investigation following complaints from the Turkish government in July that they had seized American-made weapons from the PKK, a Kurdish group considered a terrorist organization by the U.S.
CNN has received no confirmation that the probe of PKK weapons and the investigation of Blackwater employees are connected.
Iraqis were outraged by the shootings last weekend, which created new tensions between the U.S. and Iraqi governments. Iraqi officials dispute the U.S. claim that the guards were responding to an attack.
Parliament should revoke immunity to U.S. forces
The Blackwater forces should stand trial for killing Iraqi civilians according to the Iraqi Constitution, Iraqi judge Salem Rozan al-Musavi told the Mehr News Agency.
Al-Musavi also called on the Iraqi Parliament to revoke a law giving American forces in Iraq immunity from prosecution.
He said anyone who commits a crime in Iraq should stand trial in the country.
According to reports, the Blackwater forces started shooting at people randomly in the Al-Mansour region after an explosion, the cause of which was not clear, he added.
This action by the U.S. mercenaries is an intentional crime which falls under the jurisdiction of the Iraqi Constitution for prosecution, he noted.
“But some U.S. officials justify the actions of the (mercenary) company under the pretext that the company was guarding a U.S. official,” al-Musavi said.