Karimun, Batam and Bintan are the main islands in the Riau Archipelago, located just kilometres from Singapore and Malaysia.
Police separated men and women in the crowd as proceedings began, with ten men in brown robes and hoods preparing a bundle of canes in case any broke during the flogging.
The beatings were delivered on the clothed backs of the men and women, some of whom cried out in pain with each stroke.
Police in the capital, Jakarta, detained more than 140 men in a raid on a gay club on Sunday on suspicion of violating pornography laws.
Rights groups and activists have raised concern over the persecution of minorities, moral policing and violations of privacy and expression.
Although consensual sex between gay couples is allowed in most Indonesian provinces, the age of consent is 18."He was sentenced to five years because we have underaged victims.
What he committed violated the children's protection law," Didiek Jatmiko, spokesman for Mataram district court, told AFP.Bruno Gallo, 70, was found guilty of having sex with the minors, aged between 16 and 17 years old, by a judge in West Nusa Tenggara province on Wednesday.The Italian, who has lived on the island for 20 years, is accused of luring the victims to his house with money and gifts, where they agreed to have sex with him.Indonesian sex workers charge about the same for a whole night as Singaporean sex workers charge for an hour.Other luxuries, like seafood and entertainment, are much more affordable too.Some in the crowd carried banners rejecting the presence of the lesbian, gay, bisexual and transgender community in Aceh.