T

he National Police have said that six men arrested last week were directly involved in last week'€™s terrorist attack in Central Jakarta.

National Police spokesman Insp. Gen. Anton Charliyan said on Tuesday that further investigation had also shown that the remaining seven out of 13 people arrested were not part of the alleged Islamic State (IS) network responsible for the attack.

'€œSix [of the people arrested] knew directly [that the attacks would occur], because one of the perpetrators had informed them. They received a letter that looked like a will, in which they [the six] were asked to take care of [one of the perpetrators'€™] wife, children and belongings, because he was about to commit amaliyah [militant jihad],'€ Anton said, referring to one of the four suspected perpetrators, Dian Joni Kurniadi, who died in the attack.

'€œTwo of them were found not to be directly involved but supporting the attack by supplying goods,'€ he added.

Along with Muhammad Ali, Ahmad Muhazan bin Saron and Afif, Dian is believed to have launched a coordinated attack last Thursday targeting police and foreigners in a district packed with shopping centers, embassies, UN headquarters and government offices.

In the attack, Afif and Ali were killed after a bomb they were carrying detonated prematurely on the Starbucks cafe parking space, while Muhazan and Ahmad committed suicide attacks.

Three civilians died during the attack, while 26 others were sent to hospitals for treatment. A bystander in the attack, 37-year-old Rais Karna, succumbed to his injuries on Saturday.

The National Police arrested 13 people thought to be connected to the attacks.

Ten men were arrested in Cipacing, Cirebon, Bekasi and Indramayu in West Java, two in Tegal, Central Java, and one in Balikpapan, East Kalimantan.

Earlier on Monday, the Buleleng district office in Bali received a letter stating that an attack similar to the one in Jakarta could happen on the resort island.

'€œThe [letter] explained that the same group that carried out the attacks in Sarinah [Jl. Thamrin] had reached Bali and would commit similar attacks in crowded places. We have sent a team there that is currently investigating the matter, and Bali has been ordered to increase its security and vigilance,'€ he said.

Following last week'€™s attack, the government has clamped down on websites and social media accounts thought to be linked to terrorists.

Earlier, the government shut down websites and social media accounts suspected to be connected to former terror convict Muhammad Bahrun Naim, thought to be the orchestrator of the attack.

Bahrun Naim is currently fighting alongside IS in Syria.

However, several websites using Bahrun'€™s name have reappeared recently. One website, www.bahrunnaim.site, had a new post uploaded on Monday encouraging Muslims to kidnap and kill law enforcement officials and foreigners.

National Counterterrorism Agency (BNPT) chief Comr. Gen. Saud Usman Nasution told The Jakarta Post that he would work with the Communications and Information Ministry to shut down any new websites promoting radicalism.

'€œWe shut down these kinds of websites immediately, because some people are easily influenced by them and could be encouraged to join radical activities,'€ he said.

Terrorism expert Noor Huda Ismail suggested that in addition to shutting down the websites, the government should also provide a counter narrative to prevent more people from joining such groups. Noor Huda said youngsters aged 16 to 26 were particularly vulnerable to such radical influence.

'€œThe radicalization process goes like this: Websites and social media construct a reality that would later be exposed to these young kids, who then create their own meaning. This meaning is what pushes them to take action, and then this action is [displayed] on these websites. So it continues in a cycle,'€ he said.