Sudanese students demonstrate in the Red Sea city of Port Sudan on Sunday. They were protesting after four students, originally from the Darfur region, were killed last week.
In the third straight day of demonstrations, hundreds of Sudanese students in the capital Khartoum rallied to protest the deaths of four university students last week.
While the recent deaths sparked the protests, some students are also calling for the ouster of Sudanese President Omar al-Bashir.
"Revolution, revolution until victory!" has become the battle cry of the students.
Security forces beat protesters with batons and sprayed them with tear gas at Neelain University on Monday as the students chanted, "Killing a student is killing a nation."
Last week, students took part in protests at Gezira University southeast of Khartoum. Afterward, four demonstrators were found dead in a canal, and Sudanese students are blaming the security forces.
The four students were originally from Darfur, the war-torn region in western Sudan.
The Darfur Students Organization told AFP that the students died "fighting for their right to free education."
According to the 2011 Doha Document for Peace and Darfur, the children of refugees and internally displaced people affected by the war in Darfur are guaranteed five years of free education.
Al-Bashir has been in power for more than 20 years in Sudan and has been accused of widespread human rights abuses. The International Criminal Court has issued a warrant for his arrest on charges of genocide and war crimes in Darfur.
The Sudanese leader has rejected the charges, and his government has cracked down swiftly on protests following the Arab Spring uprisings that toppled leaders elsewhere in North Africa, including the neighboring states of Egypt and Libya.
Sophia Jones is an intern with NPR News.