Proposed new US immigration measures could leave many African students in the country having to reapply for visas in the middle of their degree courses.

A plan issued by the Department for Homeland Security (DHS), that is now up for discussion, outlines changes to student visas that have previously been issued for the duration of a course.

But whereas students from many countries will be allowed to get a four-year visa, there are others who will be limited to two years "due to heightened concerns related to fraud, abuse, and national security", the DHS says.

People from countries, including Sudan, listed by the US as state sponsors of terror will be affected. But by far the largest group are those from countries who have had more than 10% of their citizens overstay their visas.

This includes Nigeria, which in 2019 had an overstay rate of 13% according to government data.

Other countries affected include:

Burkina Faso

Burundi

Cameroon

Democratic Republic of Congo

Gabon

The Gambia

Liberia

Malawi

Uganda