Image copyright AFP Image caption India has the highest number of people enslaved, according to the report 
 
 Nearly 36 million people worldwide, or 0.5% of the world's population, live as slaves, a survey by anti-slavery campaign group Walk Free says. 
 
 The group's Global Slavery Index says India has the most slaves overall and Mauritania has the highest percentage. 
 
 The total is 20% higher than for 2013 because of better methodology. 
 
 The report defines slaves as people subject to forced labour, debt bondage, trafficking, sexual exploitation for money and forced or servile marriage. 
 
 It uses slavery in a modern sense of the term, rather than as a reference to the broadly outlawed traditional practice where people were held in bondage and treated as another person's property. 
 
 The Global Slavery Index's estimate is higher than other attempts to quantify modern slavery. In 2012, the International Labour Organisation estimated that almost 21 million people were victims of forced labour. 
 
 Call for action 
 
 Walk Free says it found evidence of slavery in all 167 countries it surveyed. 
 
 The report says Africa and Asia face the biggest challenges in eradicating slavery, while the practice is least prevalent in Europe. 
 
 According to the report, more than 14 million people live as slaves in India. Next in the index comes China, with more than 3 million slaves, followed by Pakistan and Uzbekistan. 
 
 Russia is ranked fifth. The country's economy is said to rely on enslaved migrant workers in the construction and agricultural sectors. 
 
 Mauritania meanwhile has the highest number of slaves as a proportion of the population, at 4%. Many people in the African country inherit their slave status from their ancestors. 
 
 Media playback is unsupported on your device Media caption HM Queen Noor of Jordan and Monique Villa, of the Thomson Reuters Foundation on slavery in the 21st Century 
 
 The report calls for much wider international cooperation on slavery. It wants governments to increase penalties for trafficking and to put pressure on businesses to clamp down on the use of slaves in their supply chains. 
 
 The Global Slavery Index was first published last year. The rise in the overall figure from 2013 was attributed by the report's authors to better data and methodology, rather than to an exponential rise in the numbers enslaved. 
 
 The UK is listed in the top 10 countries taking action against slavery. Its parliament is due to debate a law on Monday that will allow tougher sentences to be imposed for human trafficking. 
 
 Top five countries with the highest proportion of slaves 
 
 Mauritania - 4% 
 
 Uzbekistan - 3.97% 
 
 Haiti - 2.3% 
 
 Qatar - 1.36% 
 
 India - 1.14% 
 
 Figures from Global Slavery Index, 2014 ||||| Mauritania and Haiti have the highest proportions of slaves in the world. Bruno Vincent/Getty 
 
 Slavery remains a serious global problem, with 29.6 million people in various states of forced servitude, including sexual exploitation, debt bondage and forced marriage, according to a new report. 
 
 Mauritania and Haiti have the highest proportions of slaves, while India, Pakistan and China have some of the highest absolute numbers, the Walk Free Foundation said in its first Global Slavery Index report, published Wednesday. The forms of bondage violate international decrees, including the 1926 Slavery Convention, an international treaty, and the UN Trafficking Protocol. 
 
 Native-born slaves are often found in poorer countries, while exploited workers from poorer parts of the world regularly end up in rich countries where they are often trafficked. In India, some native-born slaves never leave their own villages, Walk Free found. 
 
 "Today some people are still being born into hereditary slavery, a staggering but harsh reality, particularly in parts of West Africa and South Asia," the report states. 
 
 "Other victims are captured or kidnapped before being sold or kept for exploitation, whether through 'marriage,' unpaid labor on fishing boats, or as domestic workers," the report continues. "Others are tricked and lured into situations they cannot escape, with false promises of a good job or an education." 
 
 The 10 countries with the highest number of enslaved or exploited workers, according to Walk Free, are: India, China, Pakistan, Nigeria, Ethiopia, Russian Federation, Thailand, Democratic Republic of the Congo, Myanmar and Bangladesh. 
 
 But Mauritania, with about 150,000 slaves, retains the highest proportion of enslaved people in the world, with aspects of "chattel slavery" that harken back to the American experience of the institution, where human beings are considered "full property of their masters who exercise total ownership over them and their descendants." 
 
 Many slaves in the West African nation were born into classes that have toiled as slaves for generations.
– Slavery continues to afflict almost 30 million people across the planet—in every one of 162 countries surveyed in a new report. India is home to 13.9 million slaves, by far the largest number; relative to population, however, Mauritania has the highest rate, with 4% of the population enslaved (though other groups have placed the figure as high as 20%). The new data comes from Australian activist organization Walk Free; its Global Slavery Index includes cases of human trafficking, forced labor and marriage, debt bondage, and other forms of exploitative control, Reuters notes. Three-quarters of slaves are in just 10 countries, led by China, with 2.9 million; Pakistan, with 2.1 million; Nigeria; Ethiopia; and Russia. By percentage, Mauritania—where a "chattel" system sees masters with "total ownership over (slaves) and their descendants"—is followed by Haiti, Pakistan, India, and Nepal. Iceland, meanwhile, has both the lowest number and the lowest proportion of slaves. The US has some 59,000 people experiencing such exploitation, al-Jazeera America reports. Numbers of enslaved people in wealthy countries is often "six to 10 times higher" than leaders believe, weakening anti-slavery efforts, says an expert.