The United States confirmed on Friday that 34 soldiers were diagnosed with a concussion in the brain following an Iranian missile strike on a military base in Iraq this month.
Ballistic missiles were launched at the base of Ain al-Assad in Iraq, in response to the killing of the commander of the Quds Force of the Iranian Revolutionary Guard, General Qassem Soleimani.
It is reported that traumatic brain injuries are physical injuries that are not necessarily apparent at first.
The Pentagon said that some of the soldiers have already returned to service in Iraq.
Many were taken for treatment, to places including Germany, or to return to the United States in more serious cases.
US President Donald Trump had initially announced that no soldiers were hurt in the Iranian attack.