Tamils in the north and the east observed a black day of independence on 04 February amid disruptions by the police.
Water cannons and teargas were fired at students of Jaffna University, who held a procession in Kilinochchi.
Seven students were arrested.
Tamil and social media circulated a video in which police were seen pushing aside ITAK leader S. Sritharan when he attempted to prevent an arrest.
Another student was seen dragged along the road, while several protestors were injured as they were pushed against barricades.
Amnesty International condemned the use of police power as an illegal use of force.
Sritharan and another MP, Charles Nirmalanathan, staged a sit-down protest, after which the arrested students were freed.
The TNPF organized another protest in Mullaitivu town.
Police obtained a prohibition order against another agitation planned in Batticaloa.