Along with a group of hard-liners, the Pancoran Police arrested 13 men on Saturday night at an apartment block in South Jakarta for allegedly holding “a sex party”.

Despite no strong evidence that the men had committed any crime, around 50 members of the Islam Defenders Front (FPI) barged into an apartment in the Kalibata City apartment complex and forced the police to arrest the 13 men.

Jakarta Police spokesman Sr. Comr. Raden Prabowo Argo Yuwono said Sunday the incident began after a circulated message about the alleged sex party was received by an FPI member. The member went to the unit and found a group of men not wearing any shirts before making a report to the Pancoran Police.

Escorted by the police and apartment security personnel, the mob entered the apartment and police officers took the men into custody.

However, Raden said the police were still investigating whether the men had committed any crime, saying that the only items that were confiscated during the raid were smartphones, condoms, and antiretroviral drugs for HIV patients.

“We are not sure if there was any prostitution, all we know is they were playing some games there,” Raden told reporters.

The Jakarta Post’s source, who requested anonymity due to the sensitivity of the issue, said the mob came at about 11:30 p.m. to one of the towers in the apartment complex. Members of the mob were shouting “Allahu Akbar!”

The source said the police arrived shortly after midnight.

FPI’s public relations division said on their Twitter account @HumasFPI on Sunday that the group’s “investigation unit” along with the police “successfully broken up” the alleged sex party.

The Post’s source in the police said the men had not violated any laws. In Indonesia, homosexual sodomy is not a crime except when it is done with an underage individual.

It was not the first time the police have barged into a private event following pressure from conservative religious groups.

In February, they shut down a closed workshop held by LGBT group Arus Pelangi at Cemara Hotel in Menteng, Central Jakarta.