The world celebrates International Day of the Girl today, and the United Nations Children's Fund (UNICEF) says that sub-Saharan Africa is the region of the world where the most cases of sexual abuse or violence against girls and women occur.

The region has the highest number of victims in the world: 22% of victims. It is followed by East Asia and Southeast Asia with 75 million, or 8%.

Worldwide, UNICEF estimates that sexual violence affects around 370 million girls and women. One in eight girls and women is raped or sexually assaulted before the age of 18. In sub-Saharan Africa, one in five people is sexually assaulted or raped before their 18th birthday.

UNICEF estimates that 73 million, or nine percent, were affected in Central and South Asia; 68 million, or 14%, in Europe and North America; 45 million, or 18%, in Latin America and the Caribbean and 29 million, or 15%, in North Africa and West Asia. Oceania, with six million, had the highest number of people affected in percentage terms, with 34%.

The global figure rises to 650 million, or one in five, if "non-contact" forms of sexual violence are taken into account, such as verbal or online abuse, UNICEF said in what it called the first global study into the problem. The report states that although girls and women are the most affected, between 240 and 310 million boys and men, or around one in 11, have been victims of rape or sexual assault during their childhood.

According to UNICEF, most child sexual violence occurs during adolescence, especially between the ages of 14 and 17, and those who suffer it are at greater risk of contracting sexually transmitted diseases, substance abuse and mental health problems.