India has been shamed by shocking levels of sexual assault against women, which came into sharp focus in December 2012
Praveen Sood, the police commissioner of Bangalore city, said an inquiry had been set up into allegations women attending the Saturday night celebrations were chased, groped, molested and robbed.
The announcement followed a public outcry over comments by a local minister blaming the attacks in the southern city -- an IT hub considered relatively safe for women -- on "western dress".
"As promised we have found credible evidence... We have taken action by registering a FIR (first information report). Investigation is in progress," Sood said in a series of tweets late Tuesday.
He said police had acted after going through footage from 45 CCTV cameras installed in the city centre where hundreds of revellers had gathered to celebrate the new year.
Video footage circulated on social media showed women crying and screaming for help.
The attacks in Bangalore have drawn comparison with last year's mass sexual assaults at New Year's celebrations in the German city of Cologne, where police were also accused of losing control.
India has been shamed by shocking levels of sexual assault against women, which came into sharp focus in December 2012 when a student was gang-raped on a bus in New Delhi and later died of her injuries.