Washington, DC – According to a congressional staff report out Monday, private military contractor Blackwater guards use deadly force on a weekly basis in Iraq and have inflicted “significant casualties and property damage.”

Blackwater, under investigation for the shooting deaths of 11 Iraqis on September 16, will answer questions about that incident and others at what is expected to be a testy congressional hearing on Tuesday.

Documents from Blackwater and the State Department show guards fired their weapons 195 times between from the beginning of 2005 through the second week of September, the Democratic staff of the House Oversight and Government Reform Committee found — “an average of 1.4 incidents per week,” the committee found.

“The Blackwater and State Department records reveal that Blackwater’s use of force in Iraq is frequent and extensive, resulting in significant casualties and property damage,” the staff report states.

Though the company’s contractors are authorized to use force only defensively, “the vast majority of Blackwater weapons discharges are preemptive, with Blackwater forces firing first at a vehicle or suspicious individual prior to receiving any fire.”

In another development, the FBI said it had been asked by the State Department to send a team of investigators to Iraq to look into the September 16 shootings. No criminal charges have been filed yet against Blackwater over that incident.

A report prepared by the staff of committee chair Rep. Henry Waxman, released details from Blackwater’s own reports of multiple incidents involving Iraqi civilians.