Jakarta - Radical Indonesian cleric Abu Bakar Bashir walked out of a Jakarta jail on Wednesday after serving time for links to the 2002 Bali bombings, calling on jubilant supporters to join forces for the spread of Islamic law.
Australia's prime minister said millions of his citizens would be extremely disappointed because of the release and a US embassy spokesperson said there was cause for concern.
Wearing his trademark white skullcap and red-and-white checked shawl as he emerged from prison, a smiling Bashir said: "Let us strengthen Islamic brotherhood. We strengthen our unity for one aim - that is Islamic sharia (law)".
Indonesia and other nations that "have been in darkness" could be saved by adherence to Islamic precepts, he said.
Indonesia is the world's most populous Muslim nation.
Bashir was surrounded by supporters shouting "Allahu Akbar" (God is greatest) before entering a black van for a long drive to his Islamic school, once dubbed the "Ivy League" of militants.
Seen by the West as the spiritual head of the Al-Qaeda-linked Jemaah Islamiah (JI) regional militant network, Bashir was convicted of being part of a conspiracy behind the Bali bombings that killed 202 people, many of them Australian tourists.
South-east Asian and Western authorities blame the group for the Indonesian resort island attack and other strikes.
In Australia, Prime Minister John Howard told parliament: "I want (Indonesia's politicians) to understand from me, on behalf of the government, how extremely disappointed, even distressed, millions of Australians will be at the release".
Brian Deegan, whose son, Josh, was one of 88 Australians killed in the Bali attack, told Sky television: "The cleric received a penalty that did not fit the crime."
"Abu Bashir really is to us what Osama bin Laden was to the Americans." - Reuters