Children -- most of them girls -- now make up 27 percent of all human trafficking cases, marking an alarming increase in recent years, AFP reports citing a UN agency.
Girls under 18 made up two thirds of all trafficked children and now constitute 15-20 per cent of the total number of all detected victims, the UN Office on Drugs and Crime (UNODC) said in its annual report.
The study was based on official data supplied by 132 countries from 2007-2010.
The majority of trafficked persons are women, accounting for 55 to 60 per cent of victims detected globally. However, the total proportion of women and girls together soars to about 75 per cent, according to the UNODC.
"Human trafficking requires a forceful response founded on the assistance and protection for victims, rigorous enforcement by the criminal justice system, a sound migration policy and firm regulation of the labour markets," said UNODC director Yury Fedotov in a statement.
Within the overall statistics, the study found significant regional variations.
The share of detected child victims is 68 per cent in Africa and the Middle East, and 39 per cent in South Asia, East Asia and the Pacific. The proportion drops to 27 per cent in the Americas and 16 per cent in Europe and Central Asia, according to the study.
Fedotov acknowledged gaps in knowledge about human trafficking and stressed the need for "comprehensive data about offenders, victims and trafficking flows."
Still, the number of trafficking victims is estimated to run into the millions.
The report also raises concerns about low conviction rates -- 16 per cent of reporting countries did not record a single conviction for trafficking in persons between 2007 and 2010.
On a more positive note, 154 countries have ratified the United Nations Trafficking in Persons Protocol, which the UNODC oversees.