WASHINGTON (AP) — Eleven U.S. troops were flown out of Iraq for evaluation of concussion-like symptoms in the days following an Iranian missile strike that President Donald Trump had said caused no harm to American forces, officials said Friday.

The Pentagon's chief spokesman, Jonathan Hoffman, said Defense Secretary Mark Esper did not know of the injuries until he was told Thursday afternoon that the 11 troops had been sent for evaluation at U.S. medical facilities — eight in Germany and three in Kuwait. Hoffman said the notification to Esper was in line with military procedures, which he said do not require notification of service member casualties to the Pentagon unless they involve the loss of life, limb or eyesight.

As recently as Tuesday night, Trump said he had been told no American had been harmed in the Iranian missile strike on Jan. 8. The question of American casualties was especially significant at the time because the missile attack's results were seen as influencing a U.S. decision on whether to retaliate and risk a broader war with Iran.

Trump chose not to retaliate, and the tensions with Iran have eased somewhat.

After Esper was notified of the possible brain injuries on Thursday, U.S. Central Command put out a public statement saying “several” troops were treated for concussion symptoms from the missile blasts. The AP had reported this on Monday when reporters were allowed to visit the attacked base, Ain al-Asad, in western Iraq. Thursday's statement said that “out of an abundance of caution,” some of the injured troops were flown out of Iraq for follow-on screening. Medical personnel at Ain al-Asad do not have a magnetic resonance imaging scanner, which can be used to diagnose brain injuries.

“I think everyone would agree that we could consider this an injury,” Hoffman said of the concussion symptoms, which he said became apparent over a period of days. Most or all of the troops initially resumed their military duties, he said.

One service member with concussion-like symptoms was flown out of Iraq on Jan. 10; the rest were taken out five days later, Hoffman said. He denied that anyone had downplayed the lethal potential of the Iranian missiles or delayed the reporting of the injuries out of political considerations.

“This idea that there was an effort to de-emphasize injuries for some sort of amorphous political agenda doesn't hold water," Hoffman said.