Indian students have staged one of the biggest student campus protests in recent times across the country as a student accused of sedition faces court.
Scuffles erupted outside a New Delhi courthouse between lawyers and students where Kanhaiya Kumar, 28, was to appear before a judge on Monday.
Outrage over the arrest of the left-wing student leader has led to demonstrations in at least 18 universities.
Kumar was arrested last week for sedition, after giving a speech questioning the hanging in 2013 of Mohammad Afzal Guru over his role in the 2001 attack on parliament.
Activists have long questioned Guru's conviction.
Kumar had also organized a rally to mark the anniversary of the execution of a Kashmiri separatist
Thousands of students and academics at New Delhi's prestigious Jawaharlal Nehru University (JNU) boycotted classes and erected barricades on Monday for a fourth day in an escalating conflict with the authorities.
"The government does not want students to have a say," said Rahila Parween, vice-president of the Delhi unit of the All India Students' Federation, a left-wing student union, adding, "It wants to dictate what students think, understand and say."
The incident marks another flare-up in the confrontation between Prime MInister Modi's nationalist government and left-wing and liberal groups.
Members of Modi's ruling Bharatiya Janata Party (BJP) propose strict measures against proponents of left-wing and liberal politics.
"I can assure you that every action we take is to protect our country. Any anti-India activity will not be tolerated," BJP President Amit Shah, one of Modi's closest allies, said at party headquarters.