Muslim scholars from around the world have called for female genital mutilation to be banned and those who carry it out to face punishment.
Female circumcision has been attacked as painful and dangerous
At a conference on the subject in the Egyptian capital Cairo, the scholars said governments should enforce existing laws against the practice.
Earlier, the top religious authorities in Egypt said religion offered no justification for the procedure.
Female genital mutilation is widespread in parts of Africa and the Middle East.
It is relatively unknown in most other parts of the Muslim world, including South and South-east Asia, North Africa and Saudi Arabia.
Female circumcision typically involves removing the clitoris of a young girl.
Parents who support the practice argue that it helps prevent promiscuous behaviour in their daughters.
Genital mutilation or female circumcision often robs women of sensitivity in their sexual organs.
'Do not cause harm'
The Muslim scholars said female circumcision was an aggression against women and should be stopped.
The scholars stressed that Islam forbid people from inflicting harm on others, explaining that those who circumcise their daughters were doing exactly that.
The latest declaration was unequivocal and should go a long way towards bolstering campaigns to eradicate the practice in Egypt and elsewhere, says the BBC's Heba Saleh, in Cairo.
In recent years, Muslim scholars have spoken out against female genital mutilation, but some had insisted that while it was not required by religion, it was not prohibited.
Others said it might be desirable in some cases and that it should be up to the medical profession to decide, our correspondent says.
The conference on the subject in Cairo was organised by a German human rights group, Target, and attracted Islamic clerics from across the world.
Earlier, speakers explained there was no religious reason for the practice, but hinted doctors should make any final decision.
Muhammad Sayyid Tantawi, the head of the al-Azhar mosque, Sunni Islam's top authority, told the conference: "From a religious point of view, I don't find anything that says that circumcision is a must [for women]."
"In Islam, circumcision is for men only," the Associated Press news agency quoted him as saying.
Ali Gomaa, Egypt's top official Islamic scholar, or grand mufti, told the gathering no examples of the practice could be found in the Prophet Muhammad's life.
Another leading cleric, Sheikh Yusuf al-Qaradawi, said that Islam did not require the practice but some clerics felt it was allowed.