Sponsored by the MTV End Exploitation and Trafficking campaign, a project supported by the U.S. Agency for International Development, the event was the first rock concert ever performed at the massive 12th century temple, which is a UNESCO World Heritage Site.

More than 1,200 fans turned out to see and hear The Click Five from the United States, Placebo from the United Kingdom, U.S. Grammy- and Tony Award-winner Duncan Sheik, Australian pop star Kate Miller-Heidke, Cambodian hip-hop icon Pou Klaing and Cambodian pop stars Sokun Nisa, Meas Soksophia and Chorn Sovanrech.

"We're here to call attention to human trafficking, a form of slavery that is as big a problem today as perhaps anytime in history," Placebo lead singer Brian Molko told the invitation-only audience.

The concert also featured traditional Khmer dancers and clips from "Traffic: An MTV Special," a documentary about human trafficking that was funded by the U.S. Agency for International Development, the agency said in a news release.

MTV EXIT Director Simon Goff said: "Millions of people are currently living in slavery as a result of being trafficked. This is a grotesque human-rights abuse and we must all act to stop it."