A Malaysian court has ruled that non-Muslims cannot use the word Allah to refer to God, even in their own faiths, overturning a 2009 lower court ruling.

The appeals court said the term Allah must be exclusive to Islam or it could cause public disorder.

People of all faiths use the word Allah in Malay to refer to their Gods.

Christians argue they have used the word, which entered Malay from Arabic, to refer to their God for centuries and that the ruling violates their rights.

The verdict has caused an uproar in Sabah and Sarawak, with BN political allies reported by the Malaysian Insider to be accessing the damage.

Meanwhile, Prime Minister Datuk Seri Najib Razak which is overseas has yet to give his take on the issue.