WASHINGTON, Dec. 5 -- A U. S. grand jury has indicted five employees of Blackwater Worldwide for their part in a deadly shootout in Baghdad, The New York Times reported Friday.

The indictments were sealed after being handed up Thursday but could be announced Monday, sources told the newspaper. A sixth employee was reportedly negotiating a plea agreement.

Under the current agreement with Iraq, U. S. contractors cannot be prosecuted in Iraq. The Blackwater employees were charged under a law aimed at drug dealers involving the use of weapons in violent crimes, the newspaper said.

The guards were in a convoy in Nisour Square Sept. 16, 2007, when they opened fire, killing 17 civilians. They were under contract to protect U. S. officials but were not guarding anyone at the time of the shooting.

The Blackwater employees said they were responding after being fired upon. But an investigation by the FBI determined that at least 14 of the 17 deaths could not be justified.

In 2007, the State Department reported that Blackwater had been involved in more shootings in Iraq than the other two companies providing similar services. Blackwater contractors were also involved in a 2004 incident in Fallujah. Four employees, traveling in light vehicles, were ambushed and killed. (UPI)