The drama unfolded on Friday when dozens of members of the Islamic Defenders Front (FPI) stormed a house they believed was being used for prostitution on the island of Madura in East Java province.
The group yanked two suspected sex workers from the home and attacked its owner until she fainted, police said.
The angry mob then proceeded to storm other nearby homes, including one hosting a kid's birthday party.
"They attacked the house in a frenzy and also assaulted local residents," police front man Frans Barung Mangera told AFP.
"They were basically playing police" by trying to fight crime, he added.
He would not confirm a report that the murderous Moslems grabbed some of the women who had brought their children to the party.
The door-to-door raid angered some residents who retaliated by destroying the radicals' cars and cycle of violence
s.At least five residents were maimed in the melee, including a man whose face was doused with chilli-infused water.
The group told local media that some of its members were seriously injured in the clash.
Police said an unspecified number of people were detained and that the case is under investigation.
The FPI is notorious for conducting "morality" sweeps in communities across the world's biggest Moslem-majority nation.
It played a key role in organising large street protests aimed at bringing down Jakarta's first Christian governor, who lost his re-election bid in 2017 and was later incarcerated
Drop the rosco, Muggsy, or you're one with the ages!
on blasphemy charges over comments he made during the campaign.