Juanes and John Legend performed in front of immigrants currently held in a detention center.

The two singers held a concert in front of the Eloy Immigration Detention Center, which is located in the Arizona desert about 100 miles from the Mexican border, Fusion reported. Around 1,500 immigrants are currently being held in the center, which is the second largest of its kind in the United States.

Dozens of immigration activists watched Juanes and Legend perform on a small stage in front of the facility, after workers in the center refused to let them sing inside, Fusion added. Before their performance, the duo toured the facility.

The event hoped to "bring light to our country's misguided immigration policies, and transform America's criminal justice system," the news outlet wrote. In 2015, hundreds of immigrant detainees held a hunger strike at the facility, saying that they are experiencing abuse and neglect. Ensuing reports have claimed that federal authorities have assisted in hiding mistreatment in the center.

In a video clip posted on his Instagram page, Legend, 37, said that their performance aimed to perform "how the immigration system interacts with our mass incarceration system."

"Imprisonment in all its forms is an inhumane practice," Juanes, 43, wrote on Twitter.

Both singers played two songs separately and one together -- Bob Marley's "Redemption Song," NBC News reported. Juanes played the guitar and Legend the piano situated on the top of a flatbed truck parked across the street from the facility. The empty desert field served as the backdrop, while the crowd held up huge signs and chanted "Not one more deportation" and "Si se puede" (Yes we can).

"The reason why we're here, one, is because we want to bear witness to what's happening so we could tell the world about it," Legend told the crowd, as quoted in NBC News' report.

The singers' intention was for the detainees to hear the performance, but organizers of the event were told that the inmates were not permitted outside of their cells to listen to the concert, the news outlet added. While touring the detention facility, the two spoke to the detainees inside, with Juanes saying in Spanish that he was "heartbroken" by what he witnessed.

The two recording artists also paid a visit to the Maricopa County Jail run by the controversial Sheriff Joe Arpaio, whose immigration enforcement policies resulted to a number of lawsuits, Fusion further reported.

The Eloy Detention Center has previously faced pro-immigration protests, NBC News noted. The "Dream 9" youth group was detained there for 17 days in the summer of 2013.