– For decades, Prime Minister Narendra Modi’s party and its affiliates have struggled to control one of India’s most fertile ideological recruiting grounds: university campuses.

That project erupted in violence last weekend, as masked men and women stormed the New Delhi campus of Jawaharlal Nehru University, one of India’s premier liberal institutions.

Witnesses said police officers stood by as students were attacked with rods and bricks. Some assailants shouted slogans associated with Modi’s governing party and its parent organization, the Rashtriya Swayamsevak Sangh, or RSS, which for decades has aspired to turn India into a Hindu nation.

“They pelted stones at us, stones half the size of bricks,” said Sucharita Sen, a geography professor, who was struck in the head and needed stitches. She was bleeding profusely, she said, adding: “I saw the face of terror.”

Modi’s government initially condemned the violence. But some ministers, along with others in the governing Bharatiya Janata Party, tried to justify it. “For too long, Leftists have been treated with kid gloves,” the party’s branch in the state of Karnataka said on Twitter. “No wonder this ‘good for nothing breed’ has grown like a Weed.”

As protests continue across India against Modi’s contentious citizenship law, universities have become targets, with far-right groups accused of attacking places seen as hot spots for “anti-national” activism. Some analysts saw the attack last Sunday as something more: a watershed in the ascendant Hindu nationalist movement’s fight for control over the influential university and over Indian higher education more broadly.

“For the Modi government, JNU has been a symbol of the territory they haven’t been able to capture,” said Nilanjan Mukhopadhyay, an author who has studied the RSS for years. “They are projecting it as a symbol of everything that is bad in this country and that is why they need to destroy it.”

Mukhopadhyay said the attack was a precursor to shutting down the university and “trying to reshape it.”

Students and faculty at the university said freedoms there had eroded since the election of Modi, whose government has appointed RSS-affiliated administrators to the university. In the hours after the attack, staunch supporters of Modi’s party called for the university to be closed.

While leftist ideas have long prevailed at the university and many of India’s other leading campuses, the RSS has worked to inculcate its far-right ideology at a much younger age. It runs its own network of schools and encourages children to join programs for physical training interspersed with Hindu religious rituals.

At the university level, the RSS oversees the Akhil Bharatiya Vidyarthi Parishad, one of India’s oldest and largest student unions. That group at first denied involvement in the Sunday attack.

But Anima Sonkar, a secretary for the group, said Monday that two armed men seen in a video of the assault were members of the organization. She said they had carried weapons for “self-defense,” traveling in groups and carrying rods, and in one case, acid.

Since protests began in India last month over the Citizenship Amendment Act passed by Parliament — which many see as blatantly discriminatory toward Muslims and a threat to the nation’s secular foundation — most eruptions of violence have been blamed on the police, who have been accused of torturing teenage demonstrators, lobbing tear gas canisters into a college library and killing protesters.

But the attack at Jawaharlal Nehru University, where a number of rallies against the law have been held, suggested that extremist outfits had started mobilizing against protesters, with the complicity of the authorities.

Students interviewed after the attack said the police did nothing as the mob assaulted people and chanted politically charged slogans, including “Hail Lord Ram,” a reference to a Hindu deity. That phrase has become a battle cry for Hindu nationalists.

No arrests have been made in the mob attack, though a criminal complaint has been filed against “unknown persons.” The police have said that they quickly stopped the attack, though students said it went on for well over an hour.

Pratap Bhanu Mehta, a prominent public intellectual, said the Modi government was legitimizing force against people seen as disruptive to its nationalist project, including minorities, secularists and protesters.

“There is no getting away from the fact that hunting down your own citizens as anti-national is now part of the ideological construct of this government,” he wrote in a column for the Indian Express. “The state will, directly or through proxies, encourage violence against anyone who is not in tune with it.”