About 120 million girls under the age of 20 have been forced to have sex and one fifth of homicide victims globally are under the age of 20, resulting in 95,000 deaths in 2012, according to a United Nations report released Thursday.

Drawing on data from 190 countries, the report from the UN children's agency, UNICEF, notes that children around the world are routinely exposed to violence, ranging from murder and forced sexual acts to bullying and abusive discipline in places where they should otherwise be safe.

Homicide is the leading cause of death among males between the ages of 10 and 19 in several countries in Central and South America, including Panama, Venezuela, El Salvador, Brazil, and Guatemala, UNICEF found.

In Canada, the homicide rate is two cases per 100,000 children -- half the global average. But the report raises concern about bullying, saying 32 per cent of Canadian children were involved in bullying as victims or bullies.

"Violence against children not only threatens childhoods, it erodes our society," said David Morley, UNICEF Canada president and CEO.

"Preventing violence is a shared responsibility, and we call for a national child-centred strategy in Canada to address violence in all its forms, especially for our most vulnerable children."

The report also shows the impact of violence on children has grown over the past decade. It cited a number of reasons why the phenomenon has remains largely ignored.

Violence against children in some countries is socially accepted, tacitly condoned or not seen as being abusive, UNICEF said. Or victims are too young or too vulnerable to report the crimes or the legal system can't adequately respond. Child protection services are also scarce.

"This normal everyday violence is something that we really feel like there needs a spotlight shed on it," said Susan Bissell, chief of the child protection unit at UNICEF. "What (the report) makes visible are the horrific atrocities that children experience on a daily basis everywhere in the world."

Nigeria, where the Boko Haram terrorist group abducted more than 200 schoolgirls in April and threatened to marry them off, had the largest number of young murder victims, with almost 13,000 deaths in 2012, followed by Brazil with about 11,000, the study found.

"If you look at the situation of those girls in Nigeria, they were in a school, a place that should've been a safe place," Bissell said.

Much of the violence against children is perpetrated by the people tasked with taking care of them: Caregivers, peers and partners. On average, about six in 10 children worldwide, or almost 1 billion, between the ages of two and 14 are subjected to physical punishment by their caregivers on a regular basis.

"We're not talking about a little smack on the bottom," Bissell said in an interview in her office. "We're talking about a blunt instrument, and repeated."

Sexual violence is not uncommon. Around 120 million girls worldwide, or about one in 10, have experienced forced intercourse or similarly forced acts, and one in three married adolescent girls, or about 84 million, have been victims of emotional, physical or sexual violence committed by their husbands or partners.

The prevalence of partner violence is 70 per cent or higher in the Democratic Republic of Congo and Equatorial Guinea; it approaches or exceeds 50 per cent in Uganda, Tanzania and Zimbabwe.

The report also says that children regularly experience violence in their own homes and at a young age.

Only 39 countries worldwide protect children legally from corporal punishment, the report found. Often the violence goes unreported.

One of the reasons for this is that violence seems normal. Nearly half of all girls worldwide, between 15 and 19, think a husband is sometimes justified in hitting or beating his wife, the report found.

Bissell said the report "really makes very visible things that I'd say, in many societies, that are considered not to exist, or they are normalized. They are seen just as 'the way it is,' or 'just the way it's always been."

A separate UNICEF report, also released on Thursday, lays out six strategies to prevent and respond to violence against children. The steps include providing support for families and caregivers in hopes of reducing the risk of violence within the home.

With files from The Canadian Press