UN Human Rights Commissioner Navi Pillay on Friday called for more outrage and pressure on political leaders, to bring about serious and lasting change regarding the pervasive violence against women.

Violence against women is one of the most widespread violations of human rights, but authorities too often meet such acts with indifference said the U.N. human rights chief.

"Outrage is contagious. It was the gang rape and murder of a 23-year-old physiotherapy student in New Delhi last December that unleashed what may yet become a sea-change in public attitudes towards crimes of sexual violence in India.

"This wave of public repugnance has spread, not just within India and to neighbouring countries, but further afield - including to South Africa, where the New Delhi rape was cited by activists who asked why South Africa's chronic sexual violence generates so little public anger," noted Pillay.

Her call coincided with a report published by the Christian charity World Vision highlighting that in many countries facing a humanitarian crisis, parents marry off girls early as a way of looking after them, and reducing the food demands placed on parents.

The World Vision report, Untying the Knot, is published on Friday at the United Nations in New York, where the UN Commission on the Status of Women has been meeting.

For her part Pillay highlighted three recent instances of brutal violence against women that shocked her, but that were acted upon due to outrage.

"Last month, in the highlands of Papua New Guinea, a 20-year old mother of two was stripped naked and tortured until she confessed to practicing sorcery. Then she was burned alive on the local rubbish dump in front of a crowd of fellow villagers," observed Pillay.

She noted, "Although horrific, this event was not unusual. The Constitutional and Law Reform Commission of Papua New Guinea has estimated that as many as 150 people accused of sorcery - mostly women - are murdered every year in just one of the country's 20 provinces.

Before the women are killed, many suffer prolonged, public and often sexual torture.

"Two things made last month's murder exceptional: it led to public outrage, and two alleged perpetrators have been arrested, " said Pillay.

The second case she cited happened in 'February when three sisters aged 5, 9 and 11 living in a remote Indian village were raped, killed and flung down a well.

"Initially the authorities failed to react -- but after villagers blocked a highway in protest, the police belatedly began an investigation."

The third case Pillay cited was in South Africa, also in February, when a 17-year-old girl was found horribly mutilated on a building site.

"She had been gang raped, and died hours later. Her alleged attackers were tracked down and arrested - after an unusual wave of public protests," noted Pillay, a former South African High Court judge.

The UN rights chief noted that in recent weeks, in three countries that have few features in common, widespread indifference to violence against women has, at least momentarily, given way to outcry.

"Public demands for action to end the routine atrocities so often experienced by women and girls have inspired government leaders to make important statements of intent, and stung apathetic police forces into launching investigations."

On Untying the Knot, Erica Hall, World Vision spokesperson said, "Early marriage is a brutal curtailment of childhood and a violation of children's rights, yet many parents around the world believe it is the best possible way to ensure their daughters are looked after."

Quoted on the Vision website Hall said, "We've found that early marriage is often perceived by families as a protective measure and is used by communities as a way to respond to crisis."

Of the 25 countries with the highest rates of early marriage, the majority are affected by conflict, fragility or natural disasters, the report finds. And girls trapped in early marriage tend to be poor, under-educated and living in rural areas where birth and death rates are high and where conflict is common.

Early marriage is a brutal curtailment of childhood and a violation of children's rights, yet many parents around the world believe it is the best possible way to ensure their daughters are looked after," says Erica Hall, World Vision spokesperson.

"We've found that early marriage is often perceived by families as a protective measure and is used by communities as a way to respond to crisis."

Of the 25 countries with the highest rates of early marriage, the majority are affected by conflict, fragility or natural disasters, the report finds. And girls trapped in early marriage tend to be poor, under-educated and living in rural areas where birth and death rates are high and where conflict is common.