The president of the private security company that lost seven workers within hours in Iraq mourned the loss of "seven of our friends."

"This is a very sad day for the Blackwater family," Blackwater USA (search) President Gary Jackson said in a statement Thursday.

Six Blackwater bodyguards were among 11 civilians killed Thursday when a helicopter was shot down about 12 miles north of Baghdad. A seventh Blackwater guard was killed near Ramadi (search) the same day, when a bomb exploded next to one of the company's armored personnel carriers.

It was the largest toll in a single day for the military contractor since its arm spokesman in Washington said the six killed in the helicopter crash were protecting U.S. diplomats for the Bureau of Diplomatic Security (search). The five others killed in the crash were three Bulgarians and two Fijians.

Blackwater declined to release the names of the dead until relatives were contacted. The company said it was providing the families with crisis counselors.

A Blackwater spokesman did not immediately return a call Friday seeking further details.

At least 18 Blackwater guards have died in Iraq, including four whose slaying and mutilation in Fallujah (search) made international news in March 2004. Two of the corpses were hung from a bridge, triggering a bloody three-week siege of the Sunni Muslim city west of Baghdad (search).

Iraqi insurgents again produced grisly video Thursday, which they claimed was recorded after the helicopter crash.

In the footage, which shows burning wreckage of a helicopter and two charred bodies, militants come across an injured man wearing a blue flight suit lying in tall grass.

As the survivor stands and starts to hobble at the direction of the insurgents, the gunmen open fire, shouting "Allahu akbar," or "God is great." The authenticity of the footage, posted on a Web forum often used by militant groups, could not be confirmed. The survivor in the video speaks English with an accent.