A number of American service members have traumatic brain injuries from Iranian airstrikes in Iraq, in direct contrast to President Donald Trump’s dismissal of the extent of the injuries earlier this week.

The Department of Defense revealed that 34 American troops have traumatic brain injuries, according to the New York Times. Eight of the afflicted service members returned to the U.S. after being treated in an American military hospital in Germany.

On Wednesday, Trump denied that troops felt concussion symptoms, saying they were “not very serious,” even though the Pentagon recognized that they were being considered for traumatic brain injuries as a result of the attack at Al-Asad airbase.

“I heard they had headaches,” Trump said during a news conference in Davos, Switzerland. “I don’t consider them very serious injuries relative to other injuries I have seen.”

These comments drew criticism from veteran groups. Trump famously avoided the Vietnam War after receiving a diagnosis of bone spurs.

“Don’t just be outraged by #PresidentMayhem’s latest asinine comments. Take action to help vets facing TBIs,” Paul Rieckhoff, the founder of Iraq and Afghanistan Veterans of America, tweeted.

Iran launched the missiles as retaliation for the death of a top general, Qassim Soleimani, by an American drone strike in Baghdad on Jan. 3. At first, the Trump administration contended that no one suffered injuries from the Iranian attack.

Pentagon and military officials later said that any delay in reporting the injuries was because the information took time working its way up the chain of command to leaders in Washington. They added that brain injury symptoms are not always immediately apparent.

Seventeen of the 34 troops diagnosed with traumatic brain injuries were flown by medical evacuation aircraft to Germany. Nine are still in the military hospital, while the rest have been flown back to the U.S. One person was taken to Kuwait in a medevac, while 16 troops were treated for traumatic brain injuries in Iraq and have since returned to duty.

A week following Soleimani's death, it was reported that Trump's impeachment trial impacted his decision regarding the drone strike.