An estimated 600,000 people are "tricked and trapped" into both forced employment and sexual exploitation in the Middle East, the U.N.'s labor agency said on Tuesday.

The International Labour Organisation, issuing the findings of a two-year study based on 650 interviews, called for an overhaul of employment practices in the region, notably an end to the "kafala" system of sponsorships.

"Labor migration in this part of the world is unique in terms of its sheer scale and its exponential growth in recent years," said Beate Andrees, head of an ILO program to combat forced labor.

"The challenge is how to put in place safeguards in both origin and destination countries to prevent the exploitation and abuse of these workers," she said at the opening of a two-day conference on the issue in Amman, Jordan.

The 150-page report entitled "Tricked and Trapped: Human Trafficking in the Middle East" was based on research carried out in Jordan, Kuwait, Lebanon and the United Arab Emirates.

"Although data is scarce, the ILO estimates that there are 600,000 forced labor victims in the Middle East," it said.

The study singled out the kafala system, saying it was "inherently problematic" because it created an unequal power dynamic between employers and workers.

The system "governs the lives of most migrant workers in the Mashreq and Gulf Cooperation Councils countries."

"Reforming the kafala system would significantly improve labor migration governance in this regard," it said.

The study criticized as insufficient laws that "reinforce underlying vulnerabilities of migrant workers" and restrict their ability to terminate employment contracts and to change employers.

A lack of inspections kept domestic workers isolated and heightened their "vulnerability to exploitation," said the study, warning against "the real risks of detention and deportation for workers who are coerced into sex work."

In male-dominated economic sectors such as construction, manufacturing, seafaring and agriculture, "workers are routinely deceived with respect to living and working conditions, the type of work to be performed, or even the existence of a job at all," it said.

"Human trafficking can only be effectively tackled by addressing the systemic gaps in labor migration governance across the region," said Frank Hagemann, ILO deputy regional director for Arab states.