( CNN ) -- The security firm Blackwater USA is starting to resume normal operations in Iraq after a hiatus sparked by concerns among Iraqi and U.S. government officials over its actions . Blackwater USA contractors secure the site of a roadside bombing in Baghdad in July 2005 . Tom Casey , a State Department spokesman , said on Friday that Blackwater and two other security firms that provide protection for U.S. diplomats in Iraq are resuming civilian convoys on a case-by-case basis . All Blackwater USA operations in Iraq will be back to normal on Saturday , a highly placed industry source told CNN on Friday . A deadly shooting incident on Sunday prompted the Iraqi government to bar the firm from operating . The U.S. Embassy in Baghdad has been prohibiting staff-member trips by land outside the Green Zone amid investigations into the incident . The Iraqi government has said as many as 20 civilians were killed by gunfire from Blackwater USA contractors who were guarding a U.S. diplomatic convoy . Iraqi officials dispute the U.S. claim that the guards were responding to an attack . The Blackwater employees involved in the incident are still in Iraq , but those who fired weapons -- about a third of the guards -- were `` standing down , '' said State Department spokesman Sean McCormack . Outside experts may be brought in to help review the `` protective service details '' in Baghdad , McCormack said . Such details usually have 15 to 20 guards . The `` full , complete review '' would look at rules of engagement and overall operations , with consultation with lawyers over what authority contractors operate under , he said . Sunday 's shooting has created new tension between the U.S. and Iraqi governments . U.S. Secretary of State Condoleezza Rice expressed regret about the incident in a phone call to Iraqi Prime Minister Nuri al-Maliki and promised an open and transparent probe into what happened . Watch heavily armed private contractors at work in Iraq » . `` It is extremely important to recognize we are doing important work ( in Iraq ) . We need protection for our diplomats and I am quite certain with good will we can resolve this , '' Rice said . The U.S. State Department announced Wednesday the creation of a joint commission to examine issues of security and safety in the aftermath of the shooting incident . The commission , co-chaired by an American and an Iraqi with equal representation from both countries , will receive the results of the State Department investigation and the separate Iraqi investigation , Casey said . The commission will look at the Sunday incident and the broader issue of `` personal security details '' and the use of private contractors to provide security in Iraq , he said . The commission `` is not an investigative body doing field forensics on this particular matter , '' Casey said . `` The focus of this is to look not only at that incident but at the broader question ... and help us come up with joint recommendations . '' In describing the actions of the private guards for the State Department in Iraq , McCormack said that since January 2007 there have been 1,800 movements outside the Green Zone . `` It is only a small fraction , a very small fraction , that has involved the use of force , '' he said . Security duties of companies encompass certain geographic areas in Iraq : Blackwater guards State Department officials in the Baghdad region , Tricanopy operates in the south , and Dyncorp in the north . E-mail to a friend . CNN 's Charley Keyes and Suzanne Simons contributed to this report .
State Department spokesman : Civilian patrols have resumed . Firm to resume full patrols soon , well - placed source says . Iraqi government had banned Blackwater after Sunday shooting . Company provides security for US diplomatic missions in Iraq .