An Indian court has sentenced four men to life in prison for raping a call-centre operator last year inside an abandoned textile mill in the financial hub of Mumbai.

Prosecutor Ujjwal Nikam says the court gave the maximum punishment to the four on Friday after finding them guilty of rape, unnatural sex and abduction.

It delayed until Monday the sentencing of three of the defendants and a fourth person in the rape of another woman, a photojournalist, that occurred within a month at the same location, Nikam said.

Both trials were completed in seven months by the fast-track court. Rape cases are being handled more rapidly since December 2012, when a 23-year-old medical student was fatally gang-raped on a moving bus in New Delhi.