LONDON (Thomson Reuters Foundation) - People displaced by war across the world are at heightened risk of human trafficking due to gaps in the United Nations’ response, campaigners said on Monday, calling for the creation of a new U.N. office to fight modern slavery.

Refugees and migrants cross the Old Sava Bridge heading in the direction of the Croatian border, in Belgrade, Serbia November 11, 2016. REUTERS/Marko Djurica

Nearly 46 million people around the world are living as slaves, forced to work in factories, mines and farms, sold for sex, trapped in debt bondage or born into servitude, according to the 2016 Global Slavery Index by rights group Walk Free Foundation.

Refugees are considered particularly vulnerable as poverty, insecurity and the necessity to flee war push them in the arms of traffickers who often operate with impunity in conflict areas.

Almost half of migrants traveling to Italy from North Africa said they were forced to work against their will along the way, mainly in lawless Libya, a survey by the International Organization for Migration (IOM) published last month found.

The U.N.’s response to trafficking amid the global refugee crisis has been fragmented, according to a report by Freedom Fund, an international initiative to fight slavery.

Several agencies, including the U.N.’s refugee agency (UNHCR) and the International Labour Organization (ILO) have taken steps to tackle different forms of trafficking, but with little coordination, the Freedom Fund said.

“There is a tendency for the agencies to their own thing and not be sufficiently aware of what other agencies are doing,” Freedom Fund’s CEO, Nick Grono, told the Thomson Reuters Foundation in a phone interview.

In April, a Freedom Fund report said a growing number of children whose families fled the Syrian war to Lebanon were being forced to work for little or no pay.

Interviews with humanitarian workers in conflict zones revealed they often lack proper training on what to do when dealing with a potential trafficking victim, Grono added.

In the new study published on Monday, Freedom Fund said the appointment of a U.N. special coordinator on modern slavery could help ensure anti-trafficking efforts are coordinated and more effective.

The envisioned role would answer directly to the U.N. Secretary- General and have a wider mandate and resources than existing figures, Grono said.

Several Special Rapporteurs currently operate under the U.N. Human Rights Council with focus on modern slavery including a Special Rapporteur on the sale of children, a Special Rapporteur on trafficking in persons and a Special Rapporteur on contemporary forms of slavery.

“They have minimum funding and are often effectively part-time positions,” said Grono. “We need a central responsibility”.

A spokeswoman for the U.N. Secretary-General Ban Ki-Moon stressed the U.N. was committed to eradicating modern-day slavery.

“We must end the suffering of all victims of trafficking, including those subjected to slavery, servitude, forced labor or bonded labor,” she said in a statement.