Iraqi woman looks at the blood stained car of two women allegedly shot dead by private security guards in central Baghdad, 09 Oct 2007

Iraqi officials say two women in a car were shot and killed Tuesday by private security guards escorting a convoy in Baghdad's Karrada district.

The chief operating officer of the Dubai-based security firm Unity Resources Group, Michael Priddin issued a statement saying its guards were involved in the incident. The statement says it appears that the women's vehicle was speeding toward the convoy and did not slow down despite multiple warnings from the security guards.

It adds that Unity Resources Group regrets the incident and is cooperating with Iraqi authorities.

Iraqi pedestrians run moments after a car bomb exploded in Baghdad’s central al-Khulani square during the hours of intense car traffic, 09 Oct 2007

In Washington, a U.S. State Department spokesman, Sean McCormack said the guards were not protecting a U.S. convoy.

Also Tuesday, Iraqi authorities say more than 50 people died in various attacks in the nation.

Violence included two suicide car bombings in the northern city of Baiji that killed 19 people. In Baghdad, at least 11 people died in a series of bomb blasts.

And in the northern city of Mosul, authorities say gunmen shot dead a deputy police chief.

The deadly incidents come as an Iraqi government report calls for the American security firm Blackwater USA to pay $136 million to the families of Iraqis killed in a recent shooting by the company - equal to $8 million per victim.

Blackwater says its guards responded lawfully in response to an attack on a U.S. diplomatic convoy September 16th. The Iraqi government report charges that Blackwater guards began shooting without provocation, killing 17 people.

In other news, the U.S. military says coalition forces in Iraq killed nine terrorists and detained 21 suspects during operations since Monday aimed at disrupting al-Qaida networks operating in central and northern Iraq.

Some information for this report was provided by AP and Reuters.