The suspected spiritual leader of the Al Qaeda (search)-linked Jemaah Islamiyah (search) terror group will be re-arrested after he is released from jail on Friday, a police spokesman announced. The cleric's supporters have vowed to resist the move.

Indonesian authorities earlier said Abu Bakar Bashir (search) would walk free when his 18-month term for minor immigration offenses ends Friday, despite protests from the United States and Australia, which insist he's a terrorist.

National police spokesman Maj. Gen. Bashir Ahmad Barmawi said Thursday that there is new evidence against Bashir, including witness testimony about him attending a ceremony at a militant training center in the southern Philippines in April 2000.

"Investigators will detain Bashir after he is released from the Salemba Detention Center on April 30 because police already have strong evidence about his activities," Barmawi told reporters.

Bashir's attorneys said any attempt to detain him again would be illegal.

"It's becoming clearer that the police are merely acting on behalf of Washington," said Munawarman, who like many Indonesians goes by one name. "Our client has already been proven innocent by the courts. Police can't ask anything new because they have no fresh evidence."

In March, the Supreme Court overturned a harsher treason conviction that would have kept the 66-year-old cleric behind bars for three years.

Any move to detain him could likely lead to protests by his supporters, who have vowed to resist any attempt keep him behind bars.

Dozens of Bashir's supporters have kept an around-the-clock vigil outside Jakarta's Salemba prison. They claim the United States wants him to remain in jail because of his vehement criticism of U.S. policy in the Middle East.

"We will fight back if they try to keep him (in jail) on orders of Washington," said one supporter who declined to give his name.

Bashir has consistently denied any involvement in terrorism, and on Wednesday refused to cooperate when detectives tried to grill him about the allegations.

His pending release is a sensitive political issue in Indonesia, where authorities have sought to balance the need to remain aggressive in the U.S.-led war on terror while not appearing to be caving in to foreign pressure.

Indonesians go the polls to select a new president in July, and many politicians are loath to speak out strongly against Islamic radicals during the campaign.

Many of Indonesia's top Muslim groups and politicians have spoken in Bashir's defense and demanded that Washington stop meddling in the country's domestic affairs.

Last month, U.S. Homeland Security chief Tom Ridge claimed Bashir had "intense and deep involvement in the planning and execution of terrorist activities" and should be put on trial again. Australia's foreign minister, Alexander Downer, called Bashir a "loathsome creature" and urged Jakarta not to release him.

Bashir founded a religious school, Al-Mukmin, in Solo during the 1970s. Several of the militants involved in the Bali bombings and other attacks have either taught at or had other links to the school.