London. From fist fights at school to murder and sexual abuse, each year nearly three in four children worldwide experience some form of violence, which has long term health and economic costs, a report said on Tuesday (26/09).

The study by India-based advocacy group Know Violence in Childhood found that an estimated 1.7 billion boys and girls across the globe suffer mental or physical abuse each year, with children in Africa bearing the heaviest burden.

"Childhood violence damages individuals, families and communities in both rich countries and poor," the group's co-chair Shiva Kumar told a media briefing, warning of the long-term harmful social, health and economic consequences.

Corporal punishment at home was the most common form of violence, affecting 1.3 billion children aged up to 14, said the report, which took three years to produce.

Bullying and school fights involved 138 and 123 million children aged 13 to 15 respectively, while about 18 million girls aged 15 to 19 were victims of sexual abuse.

Sexual violence was most prevalent in Africa, where more than 10 percent of girls aged 15 to 19 experienced some form abuse in their lifetime, according to the report.

The study attributed some of the violence to traditional attitudes in some societies that condone the beating of wives and children as a form of discipline.

World leaders committed to end all forms of violence against children by 2030 as part of 17 global goals adopted in 2015.

Kumar warned that childhood violence has long-term impacts, including depression, behavioral and mental problems, eating disorders and poor educational achievements.

"The damage caused by childhood violence goes far beyond immediate trauma and fear," he told a media briefing.

The report cited 2014 research which found that childhood violence costs some $7 trillion a year in loss of future productivity.

Children growing up in destitute families were at greater risk due to the additional stress that poverty put on parents, the study said.

Childhood violence was lower in countries with higher rates of child survival and where more girls attend secondary school.

The report did not include violence related to self-harm, female genital mutilation, human trafficking or conflict.

Reuters