MUMBAI—An Indian court Friday handed down death sentences for three men convicted of raping a journalist in Mumbai, in the first gang-rape case to invoke new laws dictating harsher punishment for repeat offenders.

The three men were all found guilty of two separate rapes last month. They were sentenced under new sexual-violence laws put in place after the 2012 gang rape and subsequent death of a 23-year-old student in New Delhi sparked a nationwide outcry and soul searching about women's safety in India.

Under the new laws, the minimum sentence for those convicted of more than one gang rape is life in prison and the maximum penalty is death.

The judge ruled that anything but the maximum sentence would be "ridiculous" because of the planned nature and cruelty of the rapes.

While defense lawyers said the court should show mercy as the men are still young, the judge in her final order said that in committing such "gruesome" and "diabolical" rapes, the men's ages were irrelevant, and their history as repeat offenders showed no potential for reform.