Jakarta. Police have identified Bahrun Naim, an Indonesian militant based in Syria with the Islamic State movement, as the mastermind of the blitz of bombings and gunfire that left four attackers and four others dead in downtown Jakarta last week.

Muhammad Bahrun Naim Anggih Tamtomo, or Bahrun Naim, was born in Pekalongan, Central Java, on Sept. 6, 1983. He reportedly studied IT in Solo, also in Central Java.

He served two-thirds of a two-and-half years' sentence in a Solo prison before being released on parole in 2012. He was jailed for illegal possession of firearms and explosives — not terrorism charges.

He joined IS in Syria in 2014, reportedly under the Katibah Nusantara Lid Daulah Islamiyah unit consisting mostly of Southeast Asians.

Sidney Jones, a terrorism expert at the Institute for Policy Analysis of Conflict, said the group was formed to recruit Southeast Asians who wanted to fight in Syria.

At least 250 Indonesians joined the group in Syria last year, Jones has said, adding that the Indonesian-speaking environment played a role in the group's popularity among Indonesians and Malays.

Some reports have said Bahrun attempted to recruit Indonesians to commit terror attacks in Central Java last year.

According to National Police deputy chief Comr. Gen. Budi Gunawan, Bahrun communicated extensively with Abu Jundi, a Solo-based fighter. Abu was arrested by the National Police's anti-terrorism unit Densus 88 in Carikan, Sukoharjo district, Central Java, on Dec. 19 after disappearing from the country for almost 20 years.

Just days after the November terror attacks in Paris, Bahrun published a post titled "Lessons From the Paris Attacks" to his blog, urging Indonesian militants to study the planning, coordination and "courage" of the terrorists who killed 129 people in Paris on Nov. 13.

Speaking previously to the Australian Broadcasting Corporation, Jones said Bahrun poses a greater threat than Jemaah Islamiyah's Abu Bakar Bashir — the mastermind of the 2002 and 2005 Bali bombing — who has seen his influence wane while imprisoned.

Police believe Bahrun is a supporter of jailed cleric Aman Abdurrahman — the region's most influential Indonesian militant. Bahrun was likely attempting to prove his leadership skills to IS leaders in Syria by plotting the Jakarta attack.

Bahrun's vision is to unite splintered radical groups across Southeast Asia, namely found in Indonesia, Malaysia and the Philippines, which support IS, police said.

Police arrested at least 20 terror suspects this year, all with direct or indirect links to Bahrun, over alleged plans to coordinate or finance attacks against security officials and religious minorities. Of the alleged plans only two have been executed — Thursday's attack in Jakarta and on New Year's Eve in Bandung, West Java.

It remains unclear how Bahrun raised funds for the attacks.

The two attacks, however, appeared to be poorly executed, suggesting the perpetrators had not received the same training and preparation afforded to past attacks attributed to the now largely defunct Jemaah Islamiyah regional terror network, including the 2002 and 2005 Bali bombings.

The early-2000s attacks were orchestrated by seasoned terrorists and returning combatants from places like Afghanistan, invoking concern among officials about Indonesian militants currently fighting in Iraq and Syria returning to the country at a later stage.