(CNN)A day after violence broke out in one of India's most prestigious universities, its New Delhi campus resembles a fortress, with scores of police personnel guarding its entry and exit points.
Delhi police criticized after students attacked at top university
Some students of Jawaharlal Nehru University (JNU), however, say that level of protection was nowhere to be found on Sunday, when masked men armed with iron rods and sticks entered the campus and attacked students and teachers. The violence injured around 34 people, according to police.
The students accuse police of failing to intervene while assailants shouting Hindu nationalist slogans rampaged through the university, and appeared to target left-leaning students who had been protesting against fee hikes on campus.
Three professors were among the injured. JNU staff member Sucharita Sen was pelted with stones, some as large as half a brick, by the assailants, according to a JNU Teachers' Association press briefing. With blood streaming down her face, Sen was rushed to hospital by a colleague.
The incident raises painful memories of an incident at another New Delhi university known for its liberal activism -- Jamia Millia Islamia university -- where the police were criticized for brutally handling a December student protest against a new citizenship law.
Also among the injured was Aishe Ghosh, president of the university's student union, who was beaten on the head with iron rods.
During a press conference on Monday, Ghosh accused the student wing of the country's ruling Hindu nationalist Bharatiya Janata Party (BJP) -- known as Akhil Bharatiya Vidyarthi Parishad (ABVP) -- of organizing the attack.
ABVP has denied having anything to do with the attack and blamed a rival left faction at the university for the violence.
Ghosh, whose head wound required 16 stitches, also claimed police officials and the university's security personnel did not intervene to prevent the bloodshed.
Delhi police did not respond to CNN's request for comment. However, the Deputy Police Commissioner of South East Delhi, MS Randhawa, told reporters on Monday that the police were quick to respond to the violent situation on campus.
Videos and images of the attack, which were shared on social media, sparked outrage from citizens, organizations, and politicians across party lines.
"The authorities have failed in their duty to ensure the safety of the students, signalling a shameful complicity of the state machinery," Executive Director of Amnesty International India, Avinash Kumar said in a statement.
India's main opposition Indian National Congress party wondered why "violent thugs " were able to act "with such impunity," in a tweet Sunday night. And Human Resource Development Minister, Ramesh Pokhriyal of the governing BJP party promised to take swift action.
The attack comes at a volatile time in India, after hundreds of thousands protested against a controversial citizenship law passed by the BJP in December, which fast-tracks citizenship for non-Muslim religious minorities from neighboring countries.
Protests against the law at Jamia Millia Islamia university last year led to hundreds of injuries. Students told CNN then that they were beaten by police with sticks and batons, though Delhi Police have said they were unarmed and used minimum force to bring crowds under control.