The United Nations has described the attack as “another senseless crime against migrants in the country.”
A statement by Tripoli’s interior ministry on Wednesday said the suspects — all Libyan nationals — had been detained for the attack on the man, who has not been named.
The ministry cited witness testimony that described the men storming the factory and setting the Nigerian man on fire.
War-torn Libya has repeatedly been accused of being a hostile environment for migrants and refugees, many of whom pass through the country in an attempt to reach safer shores in Europe.
Many of these migrants are intercepted by European authorities and returned to Libya.
Last month, Amnesty International released a report detailing “horrific cycles of abuses” of migrants in Libya, including unlawful killings, enforced disappearances, torture, and rape.
The rights group says that the coronavirus pandemic has exacerbated the abuse.
“Despite this, even in 2020 the EU and its member states continue to implement policies trapping tens of thousands of men, women and children in a vicious cycle of abuse, showing callous disregard for people’s lives and dignity.”
Thousands of these are believed to end up in detention centers in parts of Libya controlled by the internationally-recognized government in Tripoli.