There has been a significant rise in the number of people becoming victims of modern slavery in recent years, a new study published in London on Wednesday shows.

An estimated 50 million people were "living in situations of modern slavery" in 2021, according to the Global Slavery Index released by the human rights organization Walk Free.

That represents an increase of 10 million since a previous estimate five years ago.

The situation is deteriorating "against a backdrop of increasing and more complex armed conflicts, widespread environmental degradation" and repercussions from the COVID-19 pandemic, among other factors.

What is modern slavery?

Walk Free describes modern slavery as covering "a set of specific legal concepts including forced labor, debt bondage, forced marriage, slavery and slavery-like practices, and human trafficking."

"Modern slavery is hidden in plain sight and is deeply intertwined with life in every corner of the world. Each day, people are tricked, coerced, or forced into exploitative situations that they cannot refuse or leave. Each day, we buy the products or use the services they have been forced to make or offer without realizing the hidden human cost," the study stressed.

Forced labor accounts for 27.6 million of those in modern slavery, while forced marriage accounts for 22 million, or nearly one of every 150 people in the world, the report said.

Where is slavery most common?

North Korea (104.6 people per 1,000 population), Eritrea (90.3), and Mauritania (32) have the highest number of modern slavery victims, the report said.

Saudi Arabia, Turkey, the United Arab Emirates, and Kuwait were also among the top 10.

"These countries share some political, social, and economic characteristics, including limited protections for civil liberties and human rights," the study said.

It added that many of these regions have witnessed conflict, political instability, and/or authoritarianism, while several others are home to a large refugee and migrant worker population "who are often not afforded the same legal protections as citizens and are highly vulnerable to exploitation."

In several countries, governments force their citizens to work in different sectors, in private jails, or through forced conscription, the report said.

But there are also many people who are exploited in G20 countries. According to the report, there are 11 million people who are exploited in India, 5 million in China, and 1.8 million in Russia.