Iraqi security forces have vowed to reveal the "truth" behind the death of a 15-year-old girl killed on Tuesday.
Pro-Iran and Tehran-linked media outlets and militias have blamed "American army drills" at a "US military camp" near Baghdad Airport.
It did not mention which location the alleged gunfire referred to the former US base Camp Victory, located close to Baghdad Airport, was handed over to the Iraqi government in 2008.
This has not prevented pro-Tehran militias from blaming US forces for her death and comes after international outrage over the alleged killing of a 22-year-old woman, Mahsa Amini, by Iranian morality police.
"Baghdad Operations Command opens an investigation into the death of… Zainab Essam Majed… who was injured by a random shooting," the Iraqi Security Media Cell wrote in a statement on Twitter.
"The authorities supervising this investigation will... take the necessary legal measures against anyone who is proven to be involved in this incident."
A member of the Iran-linked Al-Fatah Alliance, Ali Al-Fatlawi, criticised "silence" amongst Iraqi leaders following Majed’s killing.
"After the killing of the girl by the fire of the American forces, we did not find anyone to defend her or demand the opening of an investigation with the American side, which caused the bloodshed of Iraqis," he said, according to The New Arab's Arabic-language service, Al-Araby Al-Jadeed.
Al-Fatlawi also claimed "there are agendas that control some silent politicians regarding the incident" and urged them to take a stand against "the repeated attacks by American forces inside Iraq".
There is no evidence US forces were involved in the shooting and no official details of the cause of the incident are known.
The US withdrew the vast majority of its forces from Iraq in 2007 and 2008, with power over its bases given to the Iraqi government.
Some US troops re-entered Iraq at the request of Baghdad in 2014, following an insurgency by the Islamic State group in an advisory and support role.
Most withdrew in 2020 and 2021 following the defeat of IS although some remain, mostly in the north of the country.
Many Iraqis have questioned the "certainty" of pro-Iran militias and activists about US involvement prior to investigations, including a researcher in Iraqi political affairs Raad Hashem.
Hashem asked on Twitter if the accusations could be "an effort to politicise [the incident] against the Americans".
Pro-Iran media have highlighted the alleged killing in response to criticism over the death of Mahsa Amini.
The New Arab has approached the US-led Inherent Resolve mission for comment.