Hundreds of protesters converged Friday on a convent that has agreed to house on parole the ex-wife and accomplice of notorious paedophile serial killer Marc Dutroux.
Several hundred people, some carrying pictures of victims or bearing white balloons, gathered at around 0830 GMT in this village in southern-central Belgium.
Others bore black balloons to show their anger at a Belgian court's decision this week to release Michelle Martin into the custody of nuns, pending a state appeal.
Martin has served half a 30-year sentence for her involvement in the kidnap, rape and deaths of two young girl victims of Dutroux in the 1990s.
On arrival at the convent, protesters hissed and cried "Shame, shame! Jail, jail! Shame on justice!"
"This release, it hurts. You have to think of the parents and the ordeal the girls suffered," said retired Albert Ponassi, who has connections to one of the families.
Paedophile Dutroux was jailed for life in June 2004 for the kidnap and rape in the 1990s of six young and teenage girls, and the murder of the four of them who died.
Martin was herself convicted in 2004 for helping Dutroux hold his victims prisoner, and of complicity in the deaths of two of the girls, found starved to death in a locked cellar.
Under Tuesday's parole ruling, former primary school teacher Martin, now 52, was ordered to "keep her distance" from relatives of victims.
Another demonstrator who asked to remain anonymous said the 16 years Martin will have served if the release is confirmed was not enough, insisting Martin "is still dangerous."
Belgium's top appeal court has another 27 days to consider the appeal.