Indonesian prosecutors sought the death penalty on Friday for the leader of a local pro-Islamic State group accused of playing a key role in the January 2016 bombings in Jakarta that killed eight people, including four attackers.

Aman Abdurrahman, 46, a radical cleric and key Islamic State figure in the country, is "legally and convincingly guilty of committing terror acts" including other attacks in 2016 and 2017, prosecutor Anita Dewayani argued during a two-hour hearing at the South Jakarta District Court.

"We request the judicial panel to sentence him to death," the prosecutor said in a packed courtroom as counterterrorism policemen and snipers guarded the court compound in the wake of a string of suicide bomb attacks in the country's second-largest city, Surabaya, early this week.

The Jan. 14, 2016, attacks, including bombings at a Starbucks outlet and a traffic police post, killed a Canadian and three other civilians, while leaving 26 people injured.

More than 40 people have been arrested in connection with the attacks -- most of them members of Jamaah Ansharut Daulah, the Islamic State-linked group set up by Aman.

(Police stand guard near the blast site after a series of explosions in Jakarta in January 2016)

Prosecutors allege Aman incited others to launch terror attacks, including the Jakarta attacks, through the "preachings he made via video call" from prison and "a book he wrote about tawhid," or the oneness of God.

Anita cited testimony from experts who said that because of his expertise in Arabic and his frequent quoting from Islamic books written in Arabic, his followers believed he always told the truth.

"Experts categorized him as an 'ideologist' because he can influence others and determine what others, including other inmates in prison, should do," the prosecutor said.

Anita claimed Aman also told his followers that if they cannot fight for Islamic State in Syria and Iraq, they should do it in "their places" of living.

Besides the Jakarta bombings, prosecutors allege Aman's involvement in four other terror attacks, including a bombing at a church in the East Kalimantan provincial capital of Samarinda in November 2016 in which a two-year-old girl was killed and five other children suffered serious burns.

He also allegedly provoked his followers to carry out bombings at the Kampung Melayu public bus terminal in East Jakarta in May last year that claimed the lives of three police officers.

Aman's trial started in mid-February, six months after he completed a prison term for a previous terrorism conviction, only for him to be arrested again upon release.

His sentence had been commuted on the occasion of the country's Independence Day.

In the series of suicide bombings in the East Java provincial capital of Surabaya, two families blew themselves up at three churches and a local police headquarters.

The fathers of the two families, and the father of another family alleged to have been making bombs for a similar suicide attack, had met Aman on the Nusakambangan prison island off the southern coast of Java Island, on Jan. 19, 2016, according to a source at the National Counterterrorism Agency.

Aman is also known to have had a hand in the Muslim extremist insurgency that engulfed the southern Philippine city of Marawi last year.

In June last year, from his prison cell, he instructed group members to join forces with Islamic State-linked militants battling with Philippine soldiers and police in the then besieged city, according to National Counterterrorism Agency chief Suhardi Alius.

Aman was earlier sentenced to seven years in prison in 2004 for a failed terror plot in Depok in the suburbs of Jakarta.

While in prison, he met Abu Bakar Bashir, spiritual leader of al-Qaida's Southeast Asia splinter group Jemaah Islamiyah, who was then serving time for terrorism.

(People mourn neart the site of an explosion in Jakarta.)

Aman was released from jail in 2008 after receiving remission for good behavior. Soon after his release, he collaborated with Bashir to form an Islamist training camp in Aceh Province in the northern part of Sumatra Island in 2010 that united different factions of terrorist groups.

His involvement in the Aceh camp landed Aman in jail again in December that year. He was sentenced to nine years in prison for financing the camp, while Bashir got 15 years.

Since late 2016, he had been held in solitary confinement at the Nusakambangan prison in a bid to curb his influence beyond prison walls.

After his imprisonment, Aman allegedly delegated the leadership of Jamaah Ansharut Daulah to Zainal Anshori, who was sentenced to seven years in prison on Monday for procuring weapons from the southern Philippines for terror attacks in Indonesia.