A day after conservative activist Laura Loomer posted videos on social media of children from Gaza arriving in the U.S. for medical treatment and questioning how they got visas, the State Department said it was halting all visitor visas for people from Gaza pending a review.

The admissions come amid widespread concern about a humanitarian crisis in Gaza after nearly two years of war that began when Hamas attacked Israel from the enclave. President Donald Trump has lamented the conditions and called on Israel to improve aid while also backing Israel’s plan to widen its military operation in the enclave.