The U.S. military says 11 service members are in hospitals after displaying concussion symptoms, following Iran’s attack last week on Iraqi bases where U.S. troops were stationed.

Iran’s ballistic missile attack on two Iraqi bases was launched in retaliation for the U.S. drone strike that killed Iran’s top general Qassem Soleimani, commander of Iran’s elite Quds Force.

Captain Bill Urban, a spokesman for U.S. Central command, said in a statement Thursday, “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.”

The service members are in hospitals in Germany and Kuwait.

“When deemed fit for duty, the service members are expected to return to Iraq,” Urban said.

U.S. President Donald Trump had said after Iran’s attack in Iraq that no U.S. forces were injured.