The number of victims of Female Genital Mutilation is 70 million higher than previously thought, according to a new Unicef report which found at least 200 million girls and women around the world had undergone the procedure.

The data is from analysis of 30 countries, including Indonesia, where FGM is prevalent despite the practice being illegal since 2006.

The statistics found that women in Indonesia, Egypt and Ethiopia account for half of all FGM victims worldwide, while Somalia has the highest percentage of women and girls aged between 15-49 having been cut, at 98 per cent.

Until now, the issue has been treated broadly as an African issue. However the most recent figures show "the practice is more global than we originally thought", Claudia Cappa, who led UNICEF's statistics team on the report, told Al Jazeera.

"In countries where data was not available, we had previously only had anecdotal evidence. We knew Indonesia has a growing population of women and girls, but I would say (these figures) are higher than expected," she said in a statement.

The data shows that FGM is more common in some Middle Eastern countries, along with Central and South Asian countries.

The majority of mutilations are done on girls under the age of five. The practice is bound up with many different cultural traditions, and in many places is conducted in the first week of life, with, or without the permission of the parents.

The report documented a case in Guinea, saying: "Two days after this Christian community celebrated Christmas in a village, five-year-old Koumba was among 11 girls that were taken into the bush, some without their parents' permission or knowledge, and others directly against strong parental protest, to receive their 'initiation'. One day later, Koumba had bled to death before she could receive medical treatment."

FGM describes the practice which involves cutting female genitalia and sometimes stitching the labia shut. It can result in infection, infertility and death, worsened because it is often carried out by traditional practitioners without technical training.

Elaine Storkey, an evangelical theologian and author of Scars Across Humanity: Understanding and overcoming violence against women, told Christian Today: "Legislation which bans FGM is crucial, as there are many countries which have no such laws and FGM is widespread and not in decline – such as in Sierre Leone where it has been declared as 'part of the country's culture by the Social Welfare and Gender Minister, Moijua Kaika.

"However, laws on their own are ineffective unless backed by a change in attitude by those who promote FGM," she added. "When FGM is seen as central to religion, vital to tradition, anti-colonial, or as a form of livelihood it continues unabated."

FGM is a key rite of many girls and women in communities where it is administered, and to refuse would risk rejection.

"It's something to be perceived as necessary for a girl to be accepted in a community where certain values and certain traditions are taking place – surrounding purity, for instance, virginity, marriageability of a girl," said UNICEF's Claudia Cappa.

The key, according to gender specialist Natalie Collins, is "the changing of hearts and minds, but this is not an easy task".

"A law can make something illegal, but if a long-held belief system puts the community in opposition to the law – especially if it's a new law – they will resist. They have other laws operating outside of the mainstream and are prioritised above national laws," she said.

Storkey added: "Awareness campaigns, community action, medical engagement and education are all vital – as are the stories of survivors who are increasingly speaking out.

"The change has to come within the countries themselves."