Residents of Ingin Jaya in Aceh Besar, Aceh province, allegedly poured sewage over two teenagers who were reportedly caught alone together in a house.
Ingin Jaya Police chief Adj. Corm. Nazarul Fitra confirmed the incident, saying that H, 18, had been visiting her boyfriend, AR, 19, when they were dragged out of the house.
"H came to the house when no one else was there. The neighbours thought they were committing immoral acts," he said, adding that investigators found no evidence to prove the allegations.
Nazarul said the police arrived late to the scene.
"The angry mob had doused [the victims] with sewage when we arrived," he said.
The couple is currently being held by sharia police Wilayatul Hisba for further legal proceedings.
"We are coordinating with the sharia police to process the case," Nazarul said.
Aceh is the only province in Indonesia to enforce sharia law, which was formally introduced in 2003 with the enactment of three bylaws banning alcohol, gambling and khalwat (socializing in secluded places).