Indonesian Anti-terror Squad shows seized firearms and items allegedly related to the Islamic State of Iraq and Syria (ISIS) from the house of a suspect who is allegedly an ISIS sympathiser in Bekasi, bordering with Jakarta, on August 14, 2023. (PHOTO / AFP)

JAKARTA — Indonesia's counter-terrorism unit on Tuesday announced the arrest of an alleged Islamic State (IS) loyalist suspected of planning an attack on the headquarters of the police's security division.

The man was detained in a raid on his house outside the capital Jakarta on Monday during which an IS flag, ammunition and 16 weapons were discovered, mostly handguns and modified air rifles, according to Aswin Siregar, spokesperson for Indonesia's Densus 88 counter-terrorism taskforce.

The suspect, an employee with a state railway company, told authorities of his plan to attack the police facility, but gave no time frame or motive

The suspect, an employee with a state railway company, told authorities of his plan to attack the police facility, but gave no time frame or motive, Aswin said.

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He added that the suspect, once a member of a defunct militant organization, had posted pro-IS content on social media and sought to raise funds for extremism via messaging app Telegram.

"We were shocked by the evidence we found," Aswin told a news conference.

"The movement of ISIS or supporters of ISIS ... has never stopped even when it's not visible to our eyes that they congregate," he said, referring to the Islamic State.

Todd Elliott, a security analyst at Concorde Consulting, said "the arrest of the suspect after a relative low in terrorist activity since the start of 2023 highlights the lingering existence of a small but highly radical minority in the country."

Indonesia, the world's largest Muslim-majority nation, suffered its worst militant attack in 2002 when two nightclubs on the island of Bali were bombed, killing 202 people, mostly foreign tourists.

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Analysts say the threat of extremist attacks has since diminished significantly and while arrests of suspected extremists do take place, pledges of allegiance to Islamic State have been rare.