Nearly three out of four children around the globe experience violence each year. That's according to a new study of children in both rich and poor countries.

What's more, the report confirms that violence in childhood is linked with violence against women. Children who witness abuse of their mothers are more likely to become victims or perpetrators of abuse when they grow up, it said.

The report, Ending Violence in Childhood: Global Report 2017, was issued by Know Violence in Childhood, an international advocacy group launched three years ago in India.

The study found that violence in childhood is nearly universal, affecting 1.7 billion children over the course of a year. This includes bullying or fighting, sexual abuse, corporal punishment at home and in school, and sexual violence.

The researchers focused on violence between the perpetrator and the child. They did not include violence from war and other events. They took more than three years to document the scale of violence experienced by millions of the world's children.

The report also looked at strategies to end the violence.

Rayma Subrahmanian, executive director of Know Violence in Childhood, said children are exposed to emotional and physical punishment from as early as 2 years old.

FILE - Adriana Maria dos Santos, mother of the late Vanessa do Santos, and a friend, Laisa, cry over Vanessa';s casket during her burial in Rio de Janeiro, Brazil, July 6, 2017. The 10-year-old child was killed two days earlier after being hit in the head

Subrahmanian said violence is a learned behavior that is rooted in deep cultural norms. In some societies, beating is a form of discipline.

Children who are victims of violence often suffer immediate harm, but they also face lifelong physical and mental health problems - anxiety, post-traumatic stress disorder, depression or attachment disorders, among others. As teens, boys are more likely to be involved with homicide and suicide. Girls are more likely to suffer sexual assault.

Violence in childhood also inflicts an economic cost on society. Know Violence in Childhood said that children who experience violence at home or at school are more likely to be absent from school or to drop out. They are less likely to succeed in life and to get an education, researchers found. Also, up to 8 percent of global GDP is spent each year on repairing the damage caused by childhood violence, the study said.

While governments can put preventive measures in place, most governments fail to invest in tackling the root causes of violence, the report said.