Story highlights Indonesian man who has spent time in jail believed to be behind Jakarta attacks

Suspect Bahrun Naim also ran a militant blog

(CNN) Bahrun Naim, the man authorities believe is the architect of Thursday's deadly attack in Jakarta, is a member of ISIS and is living in the militant jihadist group's de facto capital of Raqqa, Indonesian authorities believe.

The man, from the Javanese city of Solo, also known as Surakarta, is looking to assert himself as a major regional player in ISIS' planned " distant caliphate ."

The former blogger has spent time in prison, and has a history with radical groups, they say, adding that they believe he plotted Thursday's attack to assert himself among various figures competing to lead ISIS in Southeast Asia.

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Others include Bahrum Syah, believed to be commander of Katibah Nusantara, a joint Indonesian-Malaysian fighting unit formed in late 2014. Another is Abu Jandal, a preacher from Malang to whom Naim had links, before his ambition outgrew the influence of the iman.

Jakarta police chief Tito Karnavian told CNN that Naim went to Syria after he got out of prison.

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