Stones, allegedly thrown by members of a hardline Hindu student group, began to land among the crowd, which quickly disintegrated into chaos.
In a few cases, some students claimed, police also physically assaulted them.
At the end of the three-hour ordeal, one professor and several students and journalists were injured. Three police officers were suspended for their conduct and an administrative inquiry is ongoing, according to Dependra Pathak, a Delhi police spokesman.
Although the violence was short lived, it exacerbated a debate that has consumed India for more than a year. At stake: what makes a "good" Indian?
Self-described patriots have accused many who criticize the government of being "anti-national." It's a fight that has seen students sent to jail, injured, and has even claimed a life.
Today, some students say, they live in a period where university spaces are directly under attack.
The violence at Delhi University on February 22 started after student activist Umar Khalid was invited to discuss his research on conflict in eastern India between the government and Maoist separatists.
The local chapter of Akhil Bharatiya Vidyarthi Parishad (ABVP), a student group loosely affiliated with India's ruling Bharatiya Janata Party (BJP), protested the seminar, saying Khalid was sympathetic to Kashmiri terrorists and "anti-national."
Under pressure, the university rescinded Khalid's invitation. But on the day of the planned event, unknown assailants pelted the room where he would have appeared with stones.
The following day, students and professors from universities across Delhi gathered outside the gates of the university to march on a nearby police station and demand an investigation. That's when it turned violent.
"This was a deliberate attempt by some of these organizers who wanted to portray as if they had been attacked," said Saket Bahuguna, a national spokesman for ABVP.
He denied ABVP's involvement in the attacks and criticized those who threw stones at the seminar: "Violence has no place in a democracy."
Bahuguna, a Ph.D. student at Delhi University, said that outsiders "deliberately created chaos" during the march by students and professors.
Skinny and bookish, Umar Khalid doesn't look like a dangerous traitor. But in 2016 the Ph.D. student spent 25 days in jail, charged with sedition.
He was arrested on February 24, 2016, after he and two other students attended an event protesting a death sentence handed to a Kashmiri terrorist. Khalid said police accused them of yelling slogans favoring Pakistan and opposing India.
A self-declared Marxist and longtime student activist, Khalid said he has never engaged in any treasonous activity. But following his arrest he and fellow student Kanhaiya Kumar were pushed into the national spotlight. Their faces became synonymous with the label "anti-national."
Both men say there is no basis for their case. They point out that more than a year after their initial arrest, no official charges have been laid. Police did not respond to queries about the case.
"It's worse than the McCarthy era in the US," Khalid said. "All critics are simply being branded as anti-national."
Fear and violence
Students from Delhi and other Indian universities told CNN the protests, the violence and the arrests are a sign that dissent is increasingly becoming dangerous.
They fear the wrath of the ABVP, which is popular across India and active on most public university campuses.
According to Mukul Kesavan
, a professor at Delhi's Jamia Millia Islamia University, the ABVP is best understood as a group "informally licensed by (the BJP) to police India's universities on its behalf."
The group denies accusations it is involved in violence or intimidation of other students.
Shehla Rashid, a student activist who spoke out for Khalid after he was arrested, said the concern is that ABVP can act with impunity thanks to its ties to the government.
ABVP first came to national prominence in 2015 after Rohith Vemula, a student at Hyderabad Central University, clashed with the local chapter's president over a documentary screening. After a series of disputes, Vemula was eventually banned by the university from entering campus buildings. According to police, he subsequently committed suicide in January 2016.
Others have also complained of being targeted after criticizing ABVP. This month, a female Delhi University student said she received rape and death threats after a video she made about ABVP's protest against Khalid's seminar was published online.
Limits on speech?
Saket Bahuguna, the ABVP spokesman, says that for the group and its supporters, recent events show a clear sign of cooperation between "communist cadres" and separatist groups.
His words echo those of the country's top leaders.
"There is an alliance of subversion that is taking place, (you) have the separatist and ultra-left speaking the same language on certain university campuses," Finance Minister Arun Jaitley said at an event in London
days after the Delhi University protest.
Jaitley added that while free speech is certainly a right in a democracy, limits do exist.
"I find this absolutely strange that an argument is being raised that I have the free speech to advocate that India should be broken in to pieces," he said.
A spokesman for BJP did not respond to multiple requests for comment about ABVP and its actions.
There is a long history of government and political party involvement on university campuses in India, said Firat Unlu, an analyst with the Economist Intelligence Unit.
However, he said that the speed at which the term anti-national has been picked up shows how "right-wing groups have become increasingly emboldened."
"Right wing groups often deliberately employ terms such as 'anti-national' to undermine groups with opposing views," Unlu said.
"These slogans have become a convenient way for right-wing groups to downplay criticism and attack those with opposing views, while consolidating support within their base."
For many students, fiery political debate has given way to real fear.
"The moment you say anything apart from 'long live mother India,' you'll be branded as an anti-national," said Shehla Rashid, the student activist.
Priyanka Singh, a student council president at Doon University in the northern Indian state of Uttarakhand, experienced a version of this.
Singh found herself targeted when she attempted to hold a model parliament at her school to discuss topics like demonetization -- the controversial move by Indian Prime Minister Narendra Modi to scrap the 500 and 1,000 rupee notes in an anti-corruption push
Students who were against the event circulated a video of Singh claiming Indian soldiers had raped women in Kashmir. They called her "anti-national" and said she was promoting communism.
"They harassed me, they criticized me," she said. "This is the environment everywhere."
Kanhaiya Kumar, who was detained along with Khalid last year, said he sees cause for hope however. After his arrest, thousands turned out to demonstrate on the streets of Delhi.
"They came into the street. Not to save one person, but to save the idea of democracy," he said. "That is the basis of hope."