On April 14, 2015, on the campus of Al Fasher University in North Darfur, Sudan, riot police and members of the country’s National Intelligence Security Service (NISS) reportedly fired tear gas at crowds of nonviolent student protesters, later arresting, detaining and bringing criminal charges against a number of the students.
The student demonstrators had reportedly gathered on campus to call for regime change and a boycott of the country’s upcoming presidential elections. After dispersing the students, police reportedly took at least 18 into custody. Students were charged under Sudan’s riot act, including violating article 50 of the 1991 Sudanese Criminal Act — undermining the constitutional system — which carries the death penalty.  When they appeared in court on their first day of detention, the students reportedly showed signs of having been beaten, and had blood stains on their clothes.
Scholars at Risk is concerned about violent attacks, as well as arbitrary imprisonment and prosecution of students in retaliation for the nonviolent exercise of the right to free expression and association – conduct which is expressly protected under international human rights instruments including the Universal Declaration of Human Rights. In addition to the harm to the immediate victims, such incidents have a chilling effect on academic freedom and undermine democratic society generally. State authorities have a responsibility to protect academic freedom, freedom of expression and freedom of assembly, to refrain from violent attacks, arbitrary arrest or prosecution against students intended to limit these freedoms, and otherwise to comply with internationally recognized standards of due process, fair trial, free expression and freedom of association. 
 
SOURCES

http://www.sudouk.org/updates/updates/2015/%E2%80%8Bbrutal-attack-by-the-riot-police-and-the-niss-on-al-fasher-university-students-14th-15th-april-15.html
http://www.sudantribune.com/spip.php?article54653
https://www.amnesty.org/press-releases/2015/04/sudan-state-sponsored-assault-on-freedom-of-expression-around-elections/