On Jan. 13, U.S. soldiers stand at the site where an Iranian missile hit the Al Asad air base in Iraq earlier this month. Photo: john davison/Reuters

WASHINGTON—Nearly a dozen American troops were injured in the Iranian missile attack on two bases in Iraq last week, Defense Department officials said, after initially stating that there were no casualties in the strikes.

Eleven individuals are being screened for traumatic brain injuries following the attacks on two bases in Iraq that house American troops. Iran fired a dozen rockets total at Erbil in northern Iraq and the sprawling Al Asad air base in the west in retaliation for the American assassination of Maj. Gen. Qassem Soleimani days before. Pentagon officials at the time said there were no casualties.

But late Thursday, U.S. Central Command acknowledged that there were injuries and the 11 service members suffered concussions during the attack.

“While no U.S. service members were killed in the Jan. 8 Iranian attack on Al Asad Air base, several were treated for concussion symptoms from the blast and are still being assessed,” according to Capt. Bill Urban, a spokesman for U.S. Central Command in Tampa, Fla. “As a standard procedure, all personnel in the vicinity of a blast are screened for traumatic brain injury, and if deemed appropriate, are transported to a higher level of care.”

Eight troops were transported to Landstuhl Regional Medical Center in Germany and three others were sent to Camp Arifjan in Kuwait for screening.

Those troops are expected to return to Iraq following the screening, Capt. Urban said.

“The health and welfare of our personnel is a top priority and we will not discuss any individual’s medical status,” he said.

The revelation that there had been injuries followed a confusing week in which administration officials have struggled to explain the intelligence that led to the decision to kill Gen. Soleimani, whose death in Baghdad on Jan. 3 brought the U.S. and Iran to the brink of war. After Iran struck the two bases in Iraq, the two countries, exchanging diplomatic communications through the Swiss and others, agreed to a stand-down and tensions have eased for now.

Write to Gordon Lubold at Gordon.Lubold@wsj.com

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