The International Labour Organisation and partners point to worrying trends such as “commercial sexual exploitation” affecting nearly one in four people who are subject to forced labour and with the poor, women and children hardest hit.

ILO, along with the UN's International Organisation for Migration and the Walk Free foundation - a rights group that focuses on modern slavery - reported that 28 million people were in forced labour and 22 in forced marriages at the end of 2021.

The report released on Monday said such figures marked an increase of 10 million people living in modern slavery since the last such report was published in 2017, based on figures a year earlier. Two-thirds of the increase pertained to forced marriages alone, it said.?

Grace Forrest, founding director of Walk Free, said in an Associated Press interview in New York that the increase is about equal to the population of Greece.

The 50 million figure, she said, “is undoubtedly conservative as it has gaps from child marriage to the worst forms of child labour. So this is the baseline estimate of people living in modern slavery throughout the world."

Based on available data, ILO and partners found increases in child and forced marriages in countries like Afghanistan, Bangladesh, Congo, Egypt, India, Uganda and Yemen. But the report said wealthier countries were “not immune” to the problem, with nearly one-in-four forced marriages taking place in high or upper middle-income countries.

Crises including the coronavirus pandemic, climate change and armed conflict have underpinned rises in extreme poverty, unsafe migration, and gender-based violence in recent years, raising the risk of all forms of modern slavery, it said.?

All told, more than 2/3 of all forced marriages were found in the Asia-Pacific region – the world's most populous region – but the highest number per capita came in Arab countries where nearly 5 in 1,000 people were in forced marriages.?

Forced marriage, the report said, is closely tied to “long-established patriarchal attitudes and practices” – while 85 per cent of cases were driven by “family pressure.” Regarding forced labour, about one in eight of those affected were children and half of those in commercial sexual exploitation.

“(Modern slavery) is a man-made problem, connected to both historical slavery and persisting structural inequality,” Walk Free's Forrest said in a statement, as the ILO chief urged a broader effort to fight it.

Director-General Guy Rider of the UN labour agency, which brings together workers, businesses and governments, called for “an all-hands-on-deck approach” and said, “trade unions, employers' groups, civil society and ordinary people all have critical roles to play.”