Indonesian sharia police are "morally rehabilitating" more than 60 young punk rock fans in Aceh province on Sumatra island, saying the youths are tarnishing the province's image.

Since being arrested at a punk rock concert in the provincial capital Banda Aceh on Saturday night, 59 male and five female punk rock fans have been forced to have their hair cut, bathe in a lake, change clothes and pray.

"We feared that the Islamic sharia law implemented in this province will be tainted by their activities," Banda Aceh deputy mayor Illiza Sa'aduddin Djamal, who ordered the arrests, said.

"We hope that by sending them to rehabilitation they will eventually repent."

Hundreds of Indonesian punk fans came from around the country to attend the concert, organised to raise money for orphans.

Police stormed the venue and arrested fans sporting mohawks, tattoos, tight jeans and chains, who were on Tuesday taken to a nearby town to undergo a 10-day moral rehabilitation camp run by police.

A girl cried as women in headscarves cut her long unruly hair into a short bob, and some of the men groaned as their heads were shaved.

"Why did they arrest us? They haven't given us any reason," said Fauzal, 20.

"We didn't steal anything, we weren't bothering anyone. It's our right to go to a concert."

A 22-year-old man from Medan city who did not want to be named said he feared he would lose his job for staying at the camp for 10 days.

"I've just started with a bank in Medan. I don't even know what to tell them because I don't know why I've been arrested."