BAGHDAD – Guards working for an Australian-owned security company fired on a car as it approached their convoy Tuesday, killing two women civilians before speeding away from the latest bloodshed blamed on the deadly mix of heavily armed protection details on Baghdad’s crowded streets.

The deaths of the two Iraqi Christians – including one who used the white sedan as an unofficial taxi to raise money for her family – came a day after the Iraqi government handed U.S. officials a report demanding hefty payments and the ouster from Iraq of embattled Blackwater USA for a chaotic shooting last month that left at least 17 civilians dead.

The deaths Tuesday at a Baghdad intersection may sharpen demands to curb the expanding array of security firms in Iraq watching over diplomats, aid groups and others.

“We deeply regret this incident,” said a statement from Michael Priddin, the chief operating officer of Unity Resources Group, a security company owned by Australian partners but with headquarters in Dubai in the United Arab Emirates.

Priddin said the company would disclose more details of the shooting after “the facts have been verified and the necessary people and authorities notified.”

But initial accounts – from company statements, witnesses and others – suggested the guards opened fire as the car failed to heed warnings to stop and drifted closer to the convoy near a Unity facility in central Baghdad’s Karrahah district.

It was not immediately clear whether the guards were protecting a client at the time, but a group that uses its security agents said its personnel were not at the scene.

Four armored SUVs – three white and one gray – were about 100 yards from a main intersection in the Shiite-controlled district. As the car, a white Oldsmobile, moved into the crossroads, the Unity guards threw a smoke bomb in an apparent bid to warn the car not to come closer, said Riyadh Majid, an Iraqi policeman who saw the shooting.