(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.
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.
Sunday's shooting has created 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 »
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.