A jilted New Delhi resident upset over the marriage of his lover to another man shot her and four others dead before turning his gun on himself, a report said Tuesday.
The 25-year-old man, named as Ravi, shot the woman, her new husband and her landlady in one location on Monday morning before travelling to a suburb to kill her father and sister, the Press Trust of India news agency reported.
Ravi, who had allegedly continued his relationship with his ex-girlfriend even after her marriage over a year ago, was unhappy with her family who had prevented him from marrying her, a senior police official was quoted as saying.
Parents in India often choose husbands or wives for their children, although the trend for "love marriages" has grown during the country's economic transformation.
The Times of India said Ravi was armed with an automatic pistol and another improvised firearm.
As gun licences are difficult to obtain in India, there is a flourishing market for weapons illegally manufactured in backstreet workshops. Guns are increasingly seen as a status symbol in India.
A police spokesman was not immediately available for comment.