The Penn Museum issued an apology on Monday for its “unethical” collection of human skulls and promised to repatriate the remains of more than a dozen Black Philadelphians to be buried in a historically Black cemetery, according to The Philadelphia Inquirer.

“The Penn Museum and the University of Pennsylvania apologize for the unethical possession of human remains in the Morton Collection,” museum director Christopher Woods said in a statement. “It is time for these individuals to be returned to their ancestral communities, wherever possible, as a step toward atonement and repair for the racist and colonial practices that were integral to the formation of these collections.”

Students and community activists have held rallies in an attempt to push the museum to return the 1,000 skulls in its collection for reburial.