In a stunning blow to international scholars who had hopes of studying in the United States, the Trump administration has revoked hundreds of student visas in nearly every corner of the country as part of a vast immigration crackdown.

Dozens of schools, including the University of California and Harvard, said the Trump administration ended the visas of their students in recent days. For many, the reasons are unclear.

High-profile detentions and visa revocations are putting students on edge, as Trump tightens his squeeze on US schools.