Mark Forbes, Jakarta – A beaming Abu Bakar Bashir walked out of the gates of Cipinang jail yesterday, pledging a renewed campaign to impose sharia law on Indonesia in front of hundreds of chanting devotees.

The United States and Australian governments expressed disappointment and concern at the release of a founder and leader of the terrorist network Jemaah Islamiah.

He served less than 26 months for blessing the 2002 Bali bombings that killed 202 people. Bashir's sentence was reduced for good behaviour and to celebrate Indonesia's 61st anniversary of independence.

Wearing his trademark white skullcap, the 68-year-old cleric demanded that Indonesia's leaders save the nation from darkness by imposing sharia law on the secular state.

"We have to fight to uphold the Islamic law," he told supporters. "We have to live by the words of the prophet. Once again, we have to strengthen the Muslim brotherhood." Bashir made no mention of combating the "infidel" nations of America and Australia but a book commemorating his days in jail, published this week, is full of vitriolic attacks against Australia and the Prime Minister, John Howard.

About 40 black-jacketed Islamic bodyguards linked arms to escort Bashir through the crush to a convoy of cars and buses, to embark on a 12-hour journey to his home in Solo, central Java.

In Solo, Bashir will return to his Ngruki boarding school, dubbed the "Ivy League" of educating terrorists by the International Crisis Group. Most of the Bali bombers were graduates. He will greet students before resuming teaching there.

The Foreign Minister, Alexander Downer, said he was disappointed at the length of the sentence but accepted the decision of Indonesia's courts.

There were fears Bashir might train and inspire more terrorists, Mr Downer said. "I have some concerns about his advocacy – there's no question of that. This is somebody who believes in the jihadist principles."

A US embassy spokesman said there was deep disappointment at Bashir's release. "The possibility that a person responsible for such a terrible crime could go free after a light sentence of 30 months is cause for concern."

An Indonesian police spokesman said Bashir's release was "nothing special", but his activities would continue to be monitored. The Indonesian Foreign Minister, Hassan Wirayuda, said Bashir's release was "only a legal matter ... not a political matter".

Greeting Bashir outside the jail, the head of the Islamic Propagation Board, Hussein Umar, blamed Australian interference for Bashir's imprisonment. The claim that he headed a terrorist network was a conspiracy by the West, he said.

"Terrorism is a global issue designed by the US and its allies. They're trying to label Islam as identical to terrorism. That means every Muslim is terrorist." An organiser of the hardline Islamic Defenders Front, Eka Jaya, said linking Bashir to terrorism was a slander.

"It is a big conspiracy against Islam, and these people will carry out scorched-earth policy toward Islam." With Karuni Rompies