A "slave market" is a place where people are bought and sold as slaves, which means they are treated as property and forced to work for others without having any freedom or rights. Full definition
The men, one of them identified as a Nigerian, are victims of a growing industry of slave markets operating in several locations in Libya.» (nigeriapoliticsonline.com)
Its infamous role as the largest slave market in Eastern Africa meant that at its peak an estimated 50,000 slaves passed through the island each year until slavery was outlawed in 1873. (theexpeditioner.com)
One more thing: Dabiri also condemned the reported sale of Africans in a Libyan slave market as broadcast by CNN, saying this was unacceptable, despicable and inhuman. (nigeriapoliticsonline.com)