Jakarta: A minority Muslim group has been ordered to convert to Sunni Islam or be expelled from Bangka island, off the coast of Sumatra, in the latest religious crackdown in Indonesia.

Ahmadiyah identify as Muslim and follow the teachings of the Koran but regard an Indian preacher, Mirza Ghulam Ahmad, as a "messiah" who followed the Prophet Muhammad, a belief considered heretical by some Muslims.

Ahmadiyah refugees in Indonesia in 2011. Credit:Murdani Usman

In a letter seen by Fairfax Media, Bangka Island's most senior bureaucrat, Fery Insani, says: "The Ahmadiyah congregation are not allowed to spread their religion. Ahmadiyah followers in Srimenanti village must immediately repent in accordance with Islamic sharia that there is no prophet after the prophet Muhammad." He said if they did not abide by this a meeting had decided they must immediately leave Bangka and return to their place of origin.