Libyan activists told The Guardian Wednesday that six Libyan Christians are at risk of being executed for converting from Islam and spreading their religious beliefs.

After being arrested in March by the Libyan Internal Security Agency (ISA), the six were accused of “making people leave Islam” in violation of the Libyan Penal Code. Article 207 of the code prohibits the advocacy of ideas that would “[change] the fundamental principles of the constitution or the fundamental rules of the social structure.”

ISA also detained and later released a US citizen who was involved in Christian activities, according to local media reports.

The ISA posted videos online of the detainees confessing to their conversion and proselytism. One video showed the detained American citizen telling authorities that he and others brought in Bibles with invisible ink, readable only with a special light, to protect the privacy of those reading them.

A lawyer for another one of the detainees told The Guardian his client was tortured into renouncing his faith.

Libya has a small Christian minority, mostly made up of Coptic Orthodox Egyptians who have historical roots in the country. The interim constitution of 2011 guaranteed freedom of religion for non-Muslims, but it was suspended amid Libya’s 2014-2020 civil war.

Human Rights Watch (HRW) urged the Libyan authorities to reform the penal code in April and “redefine criminal acts to exclude peaceful exercise of the right to express opinions, assemble and establish associations.” Hannah Salah, associate Middle East and North Africa director at HRW said “Libyan authorities are crushing civic space using the tired pretext of enforcing regulations…[t]he authorities should instead be protecting that space by upholding the right to freedom of association.”