Two migrant women from Nigeria are said to have been forced to perform a “voodoo ritual” by migrant pimps in the Swedish city of Malmö and were told they must pay off their debts through prostitution or risk dying.

The two women, according to Malmö prosecutor Helena Ljunggren, were lured to Sweden by a man and a woman who also come from Nigeria with the promise of jobs. Once the pair arrived in the country, the prosecutor claims they were forced to engage in a bizarre “voodoo ritual” that included eating a raw chicken heart, broadcaster SVT reports.

“It’s about inducing the victim to pay off their debt and it’s a way to keep the victim in control. It is part of their vulnerable position. They are easy to exploit,” Ljunggren said.

Lisa Green, regional Coordinator for Trafficking in the Malmö Centre for Sexual Services, also commented on the case saying: “For those who believe in voodoo, it becomes a truth. It can be an extremely productive way of making people obey and it is usually a person in a position of power using voodoo who cannot be questioned.”

Police Bust ‘Voodoo’ Migrant Sex Slave Ring Which Forced Women ‘To Eat Raw Chicken Hearts’ https://t.co/Ch6Z5NvqTs — Breitbart London (@BreitbartLondon) February 25, 2018

Both the man and the woman involved in the trafficking are being charged in court with human trafficking and forced prostitution.

Court documents described what one woman had undergone during the “voodoo ritual” saying: “At the ritual, she was forced to eat a raw chicken heart and was cut over the chest with razor blades, after which the priest rubbed animal blood in the wounds.”

Migrant women, particularly from Africa, being forced into prostitution has also become common following the 2015 migrant crisis in countries like Italy where Nigerian gangs have taken over the entire southern coastal resort town of Castel Volturno.

“Voodoo rituals” have also been used by Nigerian gangs in Spain and the UK to control prostitutes. In February, police in both countries made 12 arrests in connection with a prostitution ring which also forced women to eat raw chicken hearts as well as have their fingernails pulled out as part of the ritual.