Egyptian newspaper al-Dustour reports that according to the Prosecutor General's Office of Libya, the victims were murdered by ISIS militants in Libya in 2015.
It's been reported that Libyan security forces arrested the alleged perpetrators of the killings, who then led authorities to the mass grave burial sites in the city of Sirte.
Libya's interior ministry told Agence France Presse: "The heads are separated from the bodies clad in orange jumpsuits, hands bound behind the back with plastic wire."
It believes these victims are connected to when the terrorist group kidnapped seven Egyptian Christians in Libya in 2013 and then captured another 14 in January 2015. It then released a video of the executions a month later.
The remains have been transferred to a lab for DNA testing.
Hundreds of Coptic Christians started fleeing Libya in the face of attacks from Islamic State in 2015. It came after the group slit the throats of 21 Christian men.
