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.

The Trump administration revoked the visas of at least two dozen more students across the country over the weekend.

Six Massachusetts institutions are among those that have confirmed that the Trump administration has terminated one or multiple student visas and student statuses at their college or universities — part of a nationwide trend.

The U.S. said on Saturday it would revoke all visas held by South Sudanese passport holders over South Sudan's failure to accept the return of its repatriated citizens, at a time when many in Africa fear that country could return to civil war.

The United States is revoking visas for South Sudanese passport holders because the country’s transitional government has not accepted citizens who were expelled from the U.S., according to the

The U.S. said on Saturday it would revoke all visas held by South Sudanese passport holders over that country’s failure of to accept the return of repatriated citizens.

South Sudan has criticized the revocation of U.S. visas for all its nationals as unfair and said it was based on an incident that didn't involve one of its citizens but another African national. U.S.

Secretary of State Marco Rubio said he was making the move because the transitional government of South Sudan had refused to accept its citizens in a timely manner.

The United States has revoked all visas held by South Sudanese passport holders, citing South Sudans refusal to accept repatriated citizens. The move, announced by U.S. Secretary of State Marco Rubio,