By Beh Lih Yi

KUALA LUMPUR (Thomson Reuters Foundation) - Malaysian student Benjamin Tan was injured and so exhausted at one point of the race that he was just limping around the running track - but he knew he could not give up.

"I was so tired, my legs were killing me but I know I was running for a greater cause to help people who are enslaved and being trafficked around the world," said the 17-year-old.

Tan was among 2,500 high school students who on Sunday completed 24 hours of relay races in a student-led campaign in Asia to end modern slavery and human trafficking.

The races were held simultaneously in Malaysia, Singapore and Hong Kong over the weekend. A similar race was held in Seoul in September.

Founded in Hong Kong in 2010 and run by students, the '24 Hour Race' initiative under the charity Running to Stop the Traffik seeks to raise awareness and funds towards combating modern slavery through the endurance race.

Tan said the race helps him to get closer to understanding the conditions of modern-day slavery, as he and his teammates cannot not quit running despite the exhaustion.

There are eight runners in each team and they take turns to run non-stop for 24 hours.

"I still won't be able to relate to what slavery victims are going through but it helps me to understand their condition a bit better. I have a choice to give up any time, slaves don't," said Tan.

Almost 46 million people around the world are living as slaves, forced to work in factories and mines, or trapped in debt bondage, according to the 2016 Global Slavery Index by the Australia-based Walk Free Foundation.

Asia, which provides low-skilled labor in global supply chains producing clothing, food and technology, accounted for two-thirds of the people in slavery, according to the index.

Another Malaysian student Michelle Lee said the race gave young people a platform to understand and explain modern slavery to the public when they embark on the fundraising campaign.

She cited the example of migrant domestic helpers who are commonly employed in Malaysian households to do cleaning and cooking but many of whom are denied their basic rights.

This includes cases of employers confiscating the domestic workers' passports or denying helpers their weekly day off.

"Modern slavery affects us on many different levels but sometimes we see it, we just don't realize that is modern slavery," said Lee, 17, who organized the Kuala Lumpur race.

The fundraising campaign this year aims to raise HK$3 million ($387,000) and the fund will be donated to six charity groups which help slavery and trafficking victims.

The campaign, which runs until mid-December, has raised about a third of its target so far, according to its chief executive Paul Balluff.

More than 150,000 students had taken part in the race in previous years.

($1 = 7.7558 Hong Kong dollars)

(Reporting by Beh Lih Yi @behlihyi, Editing by Ros Russell; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, property rights and climate change. Visit http://news.trust.org)