Sudan has been witnessing days of student protests after four students from Darfur were killed on December 5. Those students, from Gezira University, were demanding to be exempted from tuition fees - as stipulated in the July 2011 Darfur peace deal negotiated in Doha.
Darfuri students and activists say the government and "thugs" loyal to the ruling National Congress Party killed the four and threw their bodies in a canal.
Government officials deny this charge and say they are carrying out a full investigation. Of course, this was not good enough for the students in the streets.
The news of the deaths angered many students in Khartoum, who have been protesting since Sunday. They demand not only the investigation into the deaths, and that those found responsible are held to account - but also the end of President Omar al-Bashir's administration.
Students from various universities in Khartoum took to the streets, turning the city centre into a scene of chaos and running battles. Buses were set ablaze and the security forces used tear gas and batons to beat up and disperse protesters.
As protests continued on Wednesday, Darfuri students at the Islamic University in Omdurman joined those on the streets. They were attacked by security forces and National Congress Party supporters. More than 100 people were injured and many arrested. Students have since accused the attackers of setting fire to a university dormitory.
On Thursday, one of the main opposition groups, the Umma Party, held a prayer service for the deceased students. Under the banner "The death of a student is a death to a nation", opposition figures and students denounced the government. The deaths are now no longer a student issue or a Darfuri issue, they have become an issue of national concern.
The number of security personnel outside the Umma House where the event was held in Omdurman was conspicuous. In addition, plain-clothed secret police are everywhere.
Meanwhile, riot police stand guard on corners near universities and main roads. In short, the government is keen to quell the protests or prevent them from growing, and seem comfortable to use heavy-handed tactics.
But the level of anger among people here is rising - and perhaps reaching its limit. Not just because of the deaths of the students, but also the soaring prices and the rising cost of living. Just to give a few examples of the latter: When I was here last year, I used to a buy a small bag of lovely Sudanese peanuts for less than a dollar. The same bag, bought last night, cost more than $3. The price of meat has tripled, as has the price of sugar.
You can hear people whispering that they've "had enough" - but feel they can't do anything to change their situation.
Follow Omar al-Saleh on Twitter: @AJEOmar