International Harvard students say they are experiencing “pure panic” amid the Trump administration’s move to bar foreign enrollment, as students from around the world told CNN they are coming to grips with the possibility of revoked visas,

The Administration’s move is the latest escalation in its attack on elite universities across the U.S., with heavy penalties levied on Harvard, including a threat to revoke the university’s tax-exempt status. Those penalties have only grown more severe as Harvard has refused to capitulate to the Administration’s demands.

Fear and confusion mounted quickly on Thursday as international students, who make up more than a quarter of the university’s enrollment, sought clarity or reassurance.