Indonesian police said the crowd considered the sentence too lenient and were demanding the death penalty.

The incident came two days after Muslim villagers in western Java killed three members of a minority Islamic sect.

A police spokesman told the BBC that the angry crowd began attacking the court building in Temanggung after the verdict was read out.

The violence spread to surrounding neighbourhoods where two churches were set on fire and a third was damaged. Police fired warning shots into the air to disperse the crowds.

BBC