WASHINGTON – The House passed a bill Thursday that would make all private contractors working in Iraq and other combat zones subject to prosecution by U.S. courts. It was the first major response by Congress to a deadly shooting in Baghdad involving Blackwater USA security guards.

Democrats called the 389-30 vote an indictment of the incident, which left at least 13 Iraqis dead. Senate Democratic leaders said they planned to follow suit with similar legislation and send a bill to President Bush as soon as possible.

“There is simply no excuse for the de facto legal immunity for tens of thousands of individuals working in countries” on behalf of the United States, said Rep. Sheila Jackson-Lee, D-Texas.

The FBI arrived in Baghdad Thursday to investigate the Sept. 16 shooting. Bush administration officials acknowledge they are unsure whether U.S. courts would have jurisdiction in the case or others like it.

In a separate incident, a drunken Blackwater employee left a Christmas eve party in Baghdad and fatally shot the guard of one of Iraq’s vice presidents. That contractor was fired, fined and returned home to the United States; no charges have been filed.

The current law, called the Military Extraterritorial Jurisdiction Act, covers personnel supporting the mission of Defense Department operations overseas. But because Blackwater’s primary mission is to protect State Department officials, defense lawyers probably would argue the law does not apply.

At the same time, all U.S. contractors are immune from prosecution by Iraqi courts.

The bill’s passage came on the same day that a government minister told The Associated Press that the official Iraqi investigation said Blackwater security guards involved in the September incident face trial in Iraqi courts and the company should pay compensation to the victims.

The White House and congressional Republicans said they support the intent of the bill, but thought it was drafted poorly.

In a statement issued Wednesday, the White House said the bill would have “unintended and intolerable consequences for crucial and necessary national security activities and operations.” The statement did not explain further or give examples on how the bill would affect national security.

Before passage, the House voted 342-75 to ensure the legislation would not affect intelligence operations.

Rep. Chris Shays, R-Conn., accused Democrats of rushing the bill through Congress in a partisan bid to criticize the Bush administration’s handling of the war.

“It is amazing to me the number of men in Blackwater that have lost their lives and we never hear it on the other side of the aisle,” Shays said. “Blackwater is evil. That’s the way it appears in all the dialogue.”

Associated Press reporters Matthew Lee and Matt Apuzzo contributed to this report.