Police in Indonesia arrested a man for allegedly killing someone who added him to an LGBT chat group on the popular text-messaging platform WhatsApp. The 33-year-old victim, identified only as Ali, was found stabbed to death Monday night in Cawang, East Jakarta.

The suspect, 21-year-old Petrus Paulus Ualubun, was arrested in Cikarang, West Java, Tuesday morning.

"[He] was mad at the victim when he added him to an LGBT WhatsApp group," said police spokesman Argo Yuwono, reports Kompas.com.

Though Ualubun insists he's not part of the LGBT community, he invited Ali to meet. When he arrived, Ualubun reportedly stabbed him to death.

Indonesia was once considered the most moderate nation in the Muslim world, but the rise of radical factions has seen increased anti-LGBT harassment, arrests, and violence: In January, police detained 13 transgender women, shaving their heads and forcing them to dress and talk like men. A month later, Indonesia’s Health Ministry declared homosexuality a "mental disorder."

A 2016 survey found that 90% of Indonesians felt "threatened" by LGBT people. Same-sex activity is still legal in most of the country, except for sharia-governed Aceh in the north, but activists worry all-out criminalization is imminent. A bill before parliament would criminalize gay sex, as well as sex outside of marriage, with a punishment of up to five years in prison.