Christian parents whose four-year-old daughter was severely injured following an attack by an alleged Islamic extremist on a church in Borneo, Indonesia have said their faith allows them to forgive their persecutor.

Trinity Hutahaean was one of four young children injured after a man - identified by police as Juhanda, a.k.a. Jo bin Muhammad Aceng, a 32 year old ex-convict for terrorism - threw a Molotov cocktail from his passing motorbike into Oikumene Church in Samarinda, the provincial capital of E. Kalimantan province. During Sunday's attack, the man was reportedly wearing a shirt emblazoned with the phrase, "Jihad, Way of Life."

According to The Jakarta Post, Trinity's aunt Roina Simanjuntak said that the family would let God punish Juhanda,but did not wish any evil on the attacker because "God teaches us to forgive and not to pay revenge".

"I have a big hope that my family members, especially Trinity's mother, can face this hard time. She is still in trauma after seeing what happened to her child, Roina said.

She added that Trinity's mother remained patient and did not pray for God to punish Johanda: "Don't let this incident happen again in the future. [The offender] has done enough to hurt the family."

East Kalimantan police spokesman Fajar Setiawan said the toddler was playing on the church lawn with several other children at the time of the attack. As earlier reported, one of the children, 20-year-old Ade Intan Marbun, died from injuries she suffered during the attack.

After carrying out the deadly attack, Juhanda reportedly jumped into a river, where he was captured by officials. He was sentenced in 2012 to three years and six months in prison for his involvement in the "book-bomb" plot in Jakarta a year before, and received remission of sentence and was released in July 2014.

University of Indonesia (UI) terrorism expert Ridwan Habib told the outlet that Sunday's bombing was not a random incident, but a planned attack, as he had pledged allegiance to ISIS shortly before.

"He had been looking for a target: the easiest and the most vulnerable one in the area where he lived. He was not someone sent to the area to carry out the attack," he said.

The horrific attack took place just days after IS leader Abu Bakr al-Baghdadi called on all IS sympathizers to launch sporadic attacks across the globe as the terrorist group continues to lose ground in Iraq and Syria.