Students across India have been 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. The JNU has long been associated with left-wing activism, and some students have blamed Sunday's violence on a right-wing student body linked to India's governing Bharatiya Janata Party (BJP). That group denies involvement and says left-wing activists were responsible. Police say they have identified some of the assailants. However, many protesters accused police of being slow to respond to the attack. The violence has been condemned across the board, including by Defence Minister Nirmala Sitharaman and Foreign Minister S Jaishankar.