Indonesian prosecutors will bring subversion charges against 129 separatist supporters arrested in Maluku province, a police officer said.

Maluku head of detectives Chief Commissioner Usman Nasution said Monday the suspects will be charged with plotting against the state, a charge carrying up to 20 years in jail.

"The group is detained at three separate facilities and we are still waiting for prosecutors to complete the court documents," Usman told AFP by telephone from the provincial capital Ambon.

The 129 were arrested in the runup to or on April 25, the 53rd anniversary of the declaration of a Republic of South Maluku. They are accused of having sewn or flown flags of the outlawed republic.

Following the end of Dutch colonial rule, separatists proclaimed the republic in 1950 and staged a revolt against newly independent Indonesia.

The rebellion was suppressed but activists, mainly in the Netherlands, pursued a failed campaign for international recognition. Supporters of the Maluku Sovereignty Front are mainly Christians.

Front chairman Alex Manuputty and another official were sentenced to three years in jail in January for subversion. They had been arrested in Ambon in April last year after encouraging their followers to hoist separatist flags.

The independence movement does not enjoy widespread support among Christians in Maluku.

But the government of the world's largest archipelago, which faces far more serious separatist unrest in Aceh and Papua, is determined to crack down on any independence moves.