Three leading Muslim groups are against the government decision to lower the age for consensual sex, saying it will be a blow to family and social values.
Some of the groups are asking Prime Minister Manmohan Singh to withdraw the proposal.
The Jamaat Islami Hind, the All India Muslim Personal Law Board and the Muslim Majlis Mushwarat, an apex body of Muslim social and religious groups, said the move will have "dangerous consequences" for the society.
The government must abandon the proposal, they said.
"Lowering the age limit for sex outside marriage will prove detrimental for social values and India's family structure," said Nusrat Ali of Jamaat Islami Hindi.
A group of ministers headed by finance minister P Chidambaram has decided that the age for consensual sex will be lowered from 18 to 16 years. The central government formed the group to finalize the anti-rape law.
Ali said this provision would lead to "sexual anarchy" in India as school going children aged 16 and above will get involved in sexual activities.
"We are of the view that sex (outside marriage) should be a crime. It must be a punishable offense irrespective of the age limit," Ali said.
"As for lowering the age limit for consensual sex, this will lead to an unimaginable socially corrupt situation in the society.
"Not only this, this provision will increase crime against women rather than controlling it.
"We want the government to withdraw it and declare sex outside marriage a cognizable offence," he said.
Maulana Ahmed Ali Quasi of the Muslims Majlis Mushwarat shared the sentiments.
He said the government should have sought the opinion of religious groups on this sensitive issue.
"One must visualise its impact on the whole society," he said. "It will harm the Indian social system."
The All India Muslims Personal Law Board also opposed the move.
"It is an irony that the government proposes to lower the age of sex to 16 when the marriagable age is for girls in 18," senior functionary Abdul Rahim Quereshi said.
He said pre marital sex was against social norms and culture.