JAKARTA (AFP) - An Indonesian extremist who carried out a deadly attack on a church with a group of militants loyal to the Islamic State in Iraq and Syria (ISIS) militant group was jailed for life on Monday (Sept 25).

Juhanda, who like many Indonesians goes only by one name, was found guilty of an act of terrorism that killed a toddler and hurt three other small children on Borneo island last November.

"The defendant has been proven guilty of committing a terrorism act," Judge Surung Simanjuntak, from the East Jakarta Court, said.

Prosecutors said Juhanda travelled to the Protestant church in the city of Samarinda by motorbike, intending to carry out the attack.

But instead he fell from the bike and detonated a Molotov cocktail in front of the church where the youngsters, aged between two and four, had been playing.

Two-year-old Intan Olivia Marbun was killed in the blast.

Juhanda was arrested along with four others, with all five accused of belonging to the Jamaah Ansharut Daulah group (JAD), a local militant outfit that supports ISIS.

One of his co-conspirators, Joko Sugito, was jailed on Monday for seven years for his part in the attack.

The three other defendants involved in the case have received sentences ranging from six years to six years and eight months in prison.

Indonesia, which has the world's biggest Muslim population, has long struggled with Islamic militancy and has suffered a string of extremist attacks.

In 2002, a bomb in Bali exploded killing 202 people and, more recently, a suicide bombing and gun attack claimed by ISIS in the capital Jakarta killed eight people in January 2016.