NEW DELHI - An eight-month-old baby girl has been raped allegedly by her cousin in Shakurbasti, north-west Delhi, according to media reports.

The baby is reportedly in a critical condition at a local hospital where she was brought in on Sunday (Jan 28), BBC reported.

Police told the media that they had arrested the 28-year-old suspect, described as a daily wage worker.

Delhi Commission for Women chief Swati Maliwal, who visited the infant in hospital on Monday night, described her injuries as "horrific".

The incident happened on Sunday but came to light on Monday after local media reported it.

According to Times of India, police said the baby had suffered severe injuries to her vital organs and was on ventilator support at Kalawati Saran Hospital. She was in a critical condition and had undergone several surgeries.

The infant's parents had left her in the care of the mother of the suspect as they had to go to work, Times of India reported.

The baby stayed on the first floor of the house with her parents while this other family lived on the ground floor. Police said the suspect took the child to a room on the top floor of the house on the pretext of playing with her and sexually assaulted her. He had gagged the child's mouth so that her cries were inaudible.

The child's mother works as a maid nearby. When she returned home at night, she found the child crying and bleeding from her genitals profusely. She immediately rushed her to the hospital where doctors confirmed sexual assault and informed the police, Times of India said.

When the youth was questioned, he denied having anything to do with it. But soon after, he fled the house, which confirmed the police's suspicion about his involvement. He was tracked down and arrested.

He confessed to his crime during interrogation. Police said he is unmarried. The child was often left in this home with her other cousins. A case of rape under was registered at Subhash Place police station.

Meanwhile, Ms Maliwal tweeted that the girl had to undergo a three-hour operation, BBC reported.

"Her heart-rending cries could be heard in the intensive-care unit of the hospital. She has horrific injuries in her internal organs," she tweeted.

She posted another tweet expressing her anguish.

"What to do? How can Delhi sleep today when 8 month baby has been brutally raped in capital? Have we become so insensitive or we have simply accepted this as our fate?" she tweeted.

Ms Maliwal also posted a direct appeal to Prime Minister Narendra Modi that "stricter laws and more police resources" were needed to protect girls in the country.

Nearly 11,000 cases of child rape were reported in India in 2015, according to the National Crime Records Bureau's latest figures, AFP reported. Three children were raped every day in Delhi alone. The city, known as India's rape capital, hit global headlines in 2012 for the fatal gang-rape of a young female student.