Indonesia's Supreme Court has rejected the appeal of a woman whose complaint about the volume of mosque loudspeakers led to an 18-month prison sentence for blasphemy.

The ethnic Chinese woman, Meliana, was sentenced in August, more than two years after her comments sparked riots in Tanjung Balai, a port town on the island of Sumatra.

A notice on the court's website said the appeal was rejected on Mar. 27. It didn't give a reason.

The case has highlighted how Indonesia's blasphemy law has become a tool for Islamic hard-liners to persecute followers of minority religions.