Ivany Atina Arbi, Jakarta – A suicide bomber who blew himself up at Medan police headquarters in Medan, North Sumatra, on Wednesday, had pledged allegiance to a new Islamic State (IS) caliph (leader) before committing the attack, a global think tank has said.
Terrorism Research and Analysis Consortium (TRAC) revealed the information through its Twitter account @TRACterrorism on Wednesday afternoon, citing the news spread by IS supporters on their Telegram channel as its source.
"Islamic State East Asia/Jamaah Ansharut Daulah supporters claim on Telegram that suicide bomber in Medan, North Sumatra, Indonesia, pledged to new Caliph last night before the attack," the tweet said.
The TRAC is a group providing researchers in terrorism studies, international relations and other relevant fields with data and analysis about – among other things – terror attacks in the world.
Telegram, a highly encrypted messaging service, has been a favored medium and widely used by terrorist organizations to spread their propaganda and recruit members, terrorism analysts have said.
The browser version of the messaging app was blocked by the government for its rampant use among local terrorists in July 2017. However, after Telegram reportedly agreed to create a system to filter out terrorism and radicalism-related content, the government restored full access to the app in August the same year.
SITE Intelligence Group, a US-based company that tracks the online activity of jihadist organizations, has also said on its Twitter account @siteintelgroup that the Medan suicide bomber was identified as an "IS Telegram user".
The suicide bombing in Medan was the first that occurred in Indonesia following the death of former IS leader Abu Bakr al-Baghdadi, who was killed in a raid by United States special forces in northwestern Syria in late October.
In an audio tape posted online days after Baghdadi's death, the IS group warned the US to "beware vengeance [against] their nation and their brethren of infidels and apostates", Reuters has reported.
The group also said in the tape that they had appointed Baghdadi's successor, identified as Abu Ibrahim al-Hashemi al-Quraishi.
Following the attack at Medan Police headquarters, which occurred at around 8:45 a.m. on Wednesday and injured six people, authorities have identified the suicide bomber as Medan resident Rabbial Muslim Nasution, aka Dedek.
The National Police said on Thursday that Rabbial had been exposed to terrorism through his wife, identified only as DA, who had "physically interacted" with a female terrorism convict currently detained in a penitentiary in Medan.
The police had identified DA as a member of the IS-linked Jamaah Ansharut Daulah (JAD) – a homegrown terror group that was behind multiple terror attacks in Indonesia – who actively communicated with other cells in other parts of the country through social media.
"The network seems to be planning an attack on Bali," National Police spokesperson Brig. Gen. Dedi Prasetyo said on Thursday.
DA was arrested in her home in Medan by personnel of the police's Densus 88 counterterrorism squad following the attack on Wednesday.
Densus 88 had also reportedly arrested four alleged terrorists with suspected links to JAD, three of whom were arrested in Banten and one in Central Java, after the attack.
It is still unclear whether or not Rabbial was also a JAD member as the police said they were still investigating his affiliation.
A number of security analysts have suspected that the Medan suicide bombing was executed by IS supporters as a form of revenge for the death of Baghdadi, who had declared himself as caliph of all Muslims.
"We suspect that the terror attack was carried out by JAD or IS. The purpose was to avenge the death of IS leader [Baghdadi]," said Mohamad Nurzzaman, the head of the strategic study division at the country's largest Islamic group Nahdlatul Ulama (NU) youth organization as quoted by NU Online.