An official says an inmate has committed suicide by hanging herself in New Delhi's high-security prison, the second such case in four days.

Prison spokesman Sunil Gupta says the woman had been on trial in a kidnapping case for more than two years.

He said she was found hanging from a long scarf in her cell on Thursday while her cellmates were out.

On Monday, a suspect in a notorious rape case, Ram Singh, was found hanged in a cell he shared with three other prisoners. He was accused of driving a New Delhi bus on which a student was brutally raped and beaten in a crime that horrified Indians.

Tihar Jail holds 12,000 prisoners, nearly twice its intended capacity. Gupta said there have been four suicides in the past 15 months.