|Indonesia has been put on alert, amid fears that Bashir supporters might resort to violence [Reuters]
Abu Bakar Bashir, the controversial Indonesian cleric, has been jailed for 15 years on charges he helped plan and fund a camp of fighters in the western Aceh province which aimed to kill the country's president.
Indonesia has been put on alert, amid fears that Bashir supporters might indulge in acts of revenge.
Police have stepped up security, with 2,900 officers at the court alone, where phone lines were scrambled and balaclava-wearing snipers took positions on surrounding buildings.
Prosecutors had demanded a life sentence for Bashir.
Al Jazeera correspondent Step Vaessen, reporting from outside the courthouse in Jakarta, said, "For many years authorities have tried to have Bashir convicted under the country's anti-terrorism laws.
"Every time he was released, Indonesia came under scrutiny by the international community," she said.
Our correspondent said, "Bashir spent more than two years in prison over the last eight years but never on terrorism charges."
"But this time, the authorities really hope that they can lock him for many years for terrorism.
"Bashir's supporters vow to continue to fight for his release and his lawyers immediately announced they will appeal the verdict."
Sidney Jones of international crisis group told Al Jazeera: "It is a very good decision by judges."
"I am not sure whether it will have direct impact on other jehadi networks. But what we have seen many of the networks have been operating on their own without direct instructions from senior figures like Bashir.
"But it will give a chilling message to people who are active in these networks that they face very heavy sentence if they do get involved, especially if they get involved in funding and financing terrorist activities."
While, professor Tim Lindsey, head of the Centre for Islamic Law at the University of Melbourne, told Al Jazeera that "Bashir has got a strong track record of success in his appeals and he's backed by a very impressive Islamic defence legal team who've been pretty successful in the past".
"So, I think the conviction today is really the start of a process not the end of a process," he said.
Earlier, several hundred Bashir supporters greeted him with chants of "God is great" as he arrived at the court in the morning in south Jakarta under a heavy security escort including two armoured vehicles.
Some held up small banners emblazoned with "don't play around, free Abu Bakar Bashir".
Future of extremist organisations
On the question of future of extremist organisations in Indonesia, Lindsey said, "Militant Islamist groups have been active in Indonesia since 1948."
"Regardless of what happens [to Bashir] they will continue in this decades old mission to destroy the Indonesian secular state. However, their likelihood of success is extremely small."
Bashir, 72, was accused of helping to organise and fund a camp of fighters in the western Aceh province.
The Aceh camp was raided in February last year, resulting in the arrests of more than 120 people over several months.
They allegedly planned attacks on foreigners and assassinations of moderate Muslim leaders, including Susilo Bambang Yudhoyono, the Indonesian president.
Bashir denies involvement with the training camp but repeatedly defends it as legal under Islam.
Before entering the court he told reporters that the trial was an attempt by the US and Australia "to eliminate me from Indonesia".
"Give me strength to fight against the infidels, Islam's enemies," Bashir said in a prayer at the court to hundreds of his followers, many of whom travelled from other cities for the conclusion of a long trial.
It is not the first time Bashir had faced terrorism charges or spent time in detention.
He was arrested almost immediately after the Bali bombings, but prosecutors were unable to prove a string of terrorism-related allegations and reduced his four-year prison sentence to 18 months for immigration violations.
Soon after his release, he was re-arrested and sentenced to two and a half years, this time for inciting the Bali blasts, a sentence that was overturned on appeal. He was freed in 2006.
The cleric was the spiritual leader of regional group Jemaah Islamiah, blamed for the 2002 Bali bombings that killed over 200 people, mainly foreign tourists.
Bashir does not command widespread support in Indonesia, but a guilty verdict could inflame extremists, some of whom have vowed reprisals after last month's killing of Osama bin Laden by the US forces.
Underlining that risk, an anonymous text message circulating through the capital this week warned of 36 bombs exploding across the country the moment the judge announced the verdict.
Police have linked Bashir's group Jema'ah Ansharut Tauhid to many incidents of shootouts and a suicide bombing.
Indonesia has seen success in recent years in tackling extremist groups, and a period of political stability and strong economic growth has turned it into an emerging market favourite among investors.
Source: Al Jazeera and agencies