(CNN) They covered her face and laid her down. What happened next, Agnes wishes no girl would ever experience. "They grabbed my legs and arms," she said. "They excised me. Blood was coming out." Her genitals had been mutilated. Agnes, now 14, underwent the procedure in Cote D'Ivoire. But the practice is by no means limited to that one country, or even to just a few. At least 200 million women and girls in 30 countries now live with female genital mutilation, according to a new UNICEF report published in time for Saturday's International Day of Zero Tolerance for FGM, as the practice is often abbreviated. The report says 70 million more victims than previously thought have undergone the "violent practice." The exact number remains unknown. "In every case FGM violates the rights of girls and women," said UNICEF Deputy Executive Director Geeta Rao Gupta. "We must all accelerate efforts -- governments, health professionals, community leaders, parents and families -- to eliminate the practice." Under 5 years old Although female genital mutilation is carried out in many countries, the report says that more than half of those who have undergone it live in just three countries -- Indonesia, Egypt and Ethiopia. Data shows the highest rates of genital mutilation among women between the ages of 15 to 49 are in Somalia, Guinea, and Djibouti. In most countries, the majority of girls subjected to the practice are younger than 5. About one fourth of all cases worldwide were girls under the age of 14. "We start at three months," said Josephine Akissi Coulibaly, a former excisionist in Cote D'Ivoire. "They are small and we do it. Sometimes they're 18 years old. Sometimes they are mothers even. Often they bleed." FGM: Why Egyptian girls fear the summer While female genital mutilation is illegal in many countries, numerous communities consider the practice part of their cultural traditions and continue performing it. "When you try to convince an excisionist, she won't listen because it's her livelihood," said Molao Bomisso, National Director of OIS Afrique, a UNICEF partner. "But we keep insisting and insisting." FMG is often performed in conditions that lack proper hygiene, supplies and medications. As a result, the girls and women suffer infections, painful scarring, long-term disabilities and in some cases death. How you can help stop female genital mutilation 'Fear still lives inside me' The psychological trauma is immense. "This fear, I still have it inside me, because of this I was afraid of men, of boys. I didn't know if everything you did down there was painful. Up until today, that's still in my head," said Kiouala Kone, 51, who became a community activist after being subjected to genital mutilation. In recent years there has been a decline in the rates in various countries. But UNICEF said the practice remains a "global concern." It warned that the progress is not enough to keep up with population growth, and the number of cases could increase even more over the next 15 years. "Determining the magnitude of female genital mutilation is essential to eliminating the practice," said Rao Gupta, UNICEF Deputy Executive Director. "When governments collect and publish national statistics on FGM they are better placed to understand the extent of the issue and accelerate efforts to protect the rights of millions of girls and women." UNICEF hopes that with the support of governments, communities and religious leaders, the practice will be widely abandoned by 2030. "We are fighting, and the women who are going through this, they must come and fight with us. In the West, the North, the East, everywhere in the world," Bomisso said. FGM: Inside Kenya's illegal 'Cutting Room' To find out more about how you can help stop female genital mutilation, visit CNN's Impact Your World. Follow CNN Health on Facebook and Twitter. CNN's Don Melvin in London contributed to this report.