Two student leaders from Jaffna University who were detained under Sri Lanka's draconian Prevention of Terrorism Act were released on January 22.
Jaffna University Student Union president V. Bavanandan and Science Faculty student activist Shamugam Solomon were on November 29 and 30.
Jaffna University Student Union secretary P. Darshananth and Arts Faculty student union president K. Jenamejeyan remain in detention.
Jaffna is a mostly Tamil city in the north of Sri Lanka. The four student leaders were detained in late November after students at Jaffna University had defied military intimidation by lighting candles on November 27 to mark Heroes Day, when Tamils commemorate those who died fighting for an independent Tamil homeland.
The Sri Lankan government severely represses any expression of support for Tamil self-determination.
When a candle was lit in the female student hostel, soldiers broke windows and attacked the students.
The following day at least 20 students were injured when a protest rally was attacked by the army.
Following these events, students boycotted classes. Many are continuing the boycott despite the reopening of the university on January 8.