A court in India's financial hub has sentenced three men to death for at least two gang rapes.

The death sentences are the first to be handed down since India increased its penalties for sexual crimes following the gang rape and killing of a young woman aboard a private bus in New Delhi in December of 2012.

The men who were sentenced to death on Friday in the western city of Mumbai were convicted of gang raping a photojournalist in an abandoned saw mill compound last year. They were also convicted of raping another woman in the same building in a separate attack.

Also Friday, a court in southern India overturned the acquittals of 24 men involved in the case of a teenager who was raped for several weeks in southern India 18 years ago.

Kerala High Court sentenced one man to life imprisonment and the other 23 received various prison terms, ranging from seven to 11 years.

The girl was raped by at least 40 men in various places for 40 days in Kerala and Tamil Nadu. Court officials say her rapists included a professor, lawyers, businessmen, and government officials.

While the ordeal happened in 1996, the men received their acquittals in 2005. India's top court ordered a retrial last year.

India's justice system moves slowly, but the December 2012 gang rape unleashed public anger over the treatment of women and a long-unspoken epidemic of sexual violence. A strict anti-rape law and faster trials were among the changes in the legal system.