NEW DELHI-Students across India have begun protesting against an attack on a prestigious Delhi university by masked men wielding sticks on Sunday.

At least 40 students and staff of the Jawaharlal Nehru University (JNU) were admitted to hospital with injuries.

Videos of the violence quickly spread via WhatsApp and were then broadcast on television, sparking shock and outrage.

Protests are taking place in the cities of Chandigarh, Bangalore, Mumbai and Hyderabad as well as the capital Delhi.

Police have begun a probe and say they have identified some of the assailants.

The violence has been condemned across the board, including by defence minister Nirmala Sitharaman and foreign minister S Jaishankar - both of whom are alumni of the university.

What are students saying?

Protests have begun in a number of cities, with students speaking out strongly against the attack.

In Panjab university in the northern city of Chandigarh, students said that authorities had not acted swiftly enough.

“JNU has seen protests against the hostel fee hike for months now. Those protesters were detained many times and even sent to jail. But now the police is just silent about this incident - this shows us who is responsible,” Kanupriya, one of the protesters in Chandigarh, told BBC Punjabi.

The cause of the attack is still unclear. But the JNU student union blamed Sunday’s violence on the Akhil Bharatiya Vidyarthi Parishad (ABVP), a right-wing student body linked to India’s governing Bharatiya Janata Party (BJP).

But the head of the ABVP, Durgesh Kumar, said its members were the real victims - he said some of them had been injured as well.

“These goons are roaming around the campus fearlessly with batons and weapons and wearing masks. They are beating up the students of ABVP and then they are acting innocent and saying that ABVP people started the ruckus. The opposition is on their side in their manufacturing of stories. Left-leaning people are trying to defame this campus. They want to transform this campus into Naxal (Maoist rebel) camps,” he told BBC Hindi.

In the southern city of Bangalore, protesters included alumni of the university, who said something like this had never happened at JNU until now.

Maliga Sirimane, an activist present at the protest said, “JNU has been the inspiration for many struggles across the country. This is not only because it is an exemplary university, but also because of the spirit of struggle that it has even though its students have faced many atrocities.”

Students from two prominent universities in Kolkata (formerly Calcutta) have also taken out a march. “Yesterday (Sunday) was the darkest day of Indian democracy because of what happened inside the JNU campus,” one protester was quoted as saying by the PTI news agency.

What happened on Sunday at JNU?

The attack is believed to have begun close to 7pm local time (13:30 GMT) on Sunday, when a group comprising masked men and at least one woman, began attacking students. They were armed with stones, sticks and iron rods, according to students’ accounts.

“These were not small stones, these were big stones that could have broken our skulls,” Professor Atul Sood told NDTV. “I fell on the side and when I got up, I saw cars completely vandalised, including my car.”