WASHINGTON, Oct. 1 — Employees of Blackwater USA have engaged in nearly 200 shootings in Iraq since 2005, in a vast majority of cases firing their weapons from moving vehicles without stopping to count the dead or assist the wounded, according to a new report from Congress.

In at least two cases, Blackwater paid victims’ family members who complained, and sought to cover up other episodes, the Congressional report said. It said State Department officials approved the payments in the hope of keeping the shootings quiet. In one case last year, the department helped Blackwater spirit an employee out of Iraq less than 36 hours after the employee, while drunk, killed a bodyguard for one of Iraq’s two vice presidents on Christmas Eve.

The report by the Democratic majority staff of a House committee adds weight to complaints from Iraqi officials, American military officers and Blackwater’s competitors that company guards have taken an aggressive, trigger-happy approach to their work and have repeatedly acted with reckless disregard for Iraqi life.

But the report is also harshly critical of the State Department for exercising virtually no restraint or supervision of the private security company’s 861 employees in Iraq. “There is no evidence in the documents that the committee has reviewed that the State Department sought to restrain Blackwater’s actions, raised concerns about the number of shooting episodes involving Blackwater or the company’s high rate of shooting first, or detained Blackwater contractors for investigation,” the report states.