A group of at least 32 foreigners have been detained in Baghdad after an Iraqi woman was shot and injured, say Iraqi government officials.
Some of those detained are said to be private security guards
Among those held are private security guards, with early reports saying two Americans were among those held. The US military later said none were arrested.
The incident occurred as guards tried to clear the way for their convoy in a traffic jam, an Iraqi official said.
The Iraqi government has vowed to crack down on the conduct of security firms.
In the United States, an investigation is under way after 17 Iraqi civilians were shot dead by guards working for the North Carolina-based Blackwater firm on 16 September.
The latest shooting incident occurred on Monday.
Brigadier General Qasim Ata of the Iraqi army told AFP news agency the suspects had "opened fire randomly on citizens in Karrada" district of Baghdad, and a woman had been wounded.
"They are in custody now and the incident is under investigation," he was quoted as saying.
The woman's condition is unknown.
Two Americans working as guards for the firm are among those in detention, spokesmen for the Iraqi government and the Iraqi military told news agencies.
Also in detention are some of the foreign workers - now reported to include Sri Lankans and Nepalese - whom the guards were escorting through Karrada district when the shooting incident allegedly happened.
Ten Iraqis were also detained.
It is unclear at present which of the detainees is accused of the shooting.
The private security firm in question has not been identified. Early statements from Iraqi officials suggested it was Italian.
Italy's foreign ministry says it believes no Italians were among those arrested.
After the arrests, Iraqi government spokesman Ali al-Dabbagh told Reuters news agency that those held would appear before an investigating judge in Baghdad on Tuesday.
"This is a message to security companies that no one is above the law," Mr Dabbagh said
"Those involved will be put on trial and the innocent will be released."
In the wake of the Blackwater controversy, the Iraqi government promised it would crack down on the activities of the multiple foreign security contractors operating in the country.
At the end of October it approved a draft law revoking their immunity from prosecution.