Delhi Police Commissioner Neeraj Kumar said four people had been arrested for what is amongst the most horrific rape incidents ever reported, putting the spotlight on the vulnerability of women in India's national capital.
Those arrested were bus driver Ram Singh, his brother Mukesh, fruit seller Pawan Gupta and Vinay Sharma, an instructor in the Delhi government-run gym in Siri Fort.
Two others, Akshay Thakur and Raju, were absconding.