"As of today, 50 U.S. service members have been diagnosed with TBI," Defense Department spokesman Lt. Col. Thomas Campbell said in a statement, referring to traumatic brain injury.

Of them, 31 were treated in Iraq and returned to duty, including 16 of the additional service members who have been diagnosed since the previous report, said Campbell

"Eighteen service members have been transported to Germany for further evaluation and treatment," he added.

Last week, the Pentagon put the number of injured at 34.

U.S. President Donald Trump initially said no U.S. troops were injured in the Jan. 8 airstrikes, which Iran carried out in retaliation for the U.S. assassination of its top general for regional operations, Qassem Soleimani.

But the casualty toll was updated by the Pentagon days later when it said on January 17 that 11 service members had been diagnosed with traumatic brain injuries.

Addressing reporters in Davos, Switzerland earlier this week, Trump said he "heard that they had headaches, and a couple of other things," calling the injuries "not very serious."

Reporter’s code: 50101