Updated at 3:14 p.m. ET on 2019-11-15
Indonesian authorities said Friday they had arrested 19 militant suspects at several locations across the archipelago as part of their probe into this week’s suicide bombing that targeted a police headquarters in Medan, the capital of North Sumatra province.
The suspects were taken into custody during raids by law enforcement officers on Sumatra, Java and Ambon islands in the wake of Wednesday’s attack, which injured six people, including four policemen, the national police chief said.
“As part of the investigation into the case, we have arrested about 19 people,” Gen. Idham Azis, the country’s top police officer, told reporters during a visit to Palu in Central Sulawesi province. “Whether they are part of an old network, we are still investigating.”
He did not provide more details.
National police spokesman Dedi Prasetyo said one of the 19 suspects worked at Krakatau Steel, a state-owned steel mill in Banten province.
“We will reveal his role later,” Dedi told BenarNews. The 54-year-old suspect was arrested along with two other people on Wednesday, he said.
Another police spokesman, Muhammad Iqbal, said security has been beefed up at police stations across the country after the bombing.
Police have been targets of attacks by Islamist militants in Indonesia in recent years.
“Those who wear jackets or carry rucksacks will be subjected to checks. I appeal to the public to understand if our colleagues conduct such checks. It’s not that we are not friendly, we are just taking preventive measures,” Iqbal said.
Police have identified Rabbial Muslim Nasution, a 24-year-old Medan-born university student as the suspect in Wednesday’s bombing, which they initially described as a “lone-wolf” attack.
They said Rabbial set off an explosive belt outside city police headquarters after passing through a routine security check at the entrance. He was the lone fatality in the explosion.
On Thursday, police said Rabbial’s widow, whom authorities identified only by her initials, D.A., had talked with a female inmate at the Medan women’s prison about plotting an attack on Bali, the country’s most popular tourist destination.
Dedi said Rabbial might have been radicalized by his wife. She was among the 19 suspects arrested in connection with the Medan attack.
Supporters of Jamaah Ansharut Daulah (JAD), an Indonesian militant network affiliated with Islamic State (IS), claimed via online messaging that Rabbial had pledged allegiance to its new caliph, Abu Ibrahim al-Hashemi al-Quraishi, on the eve of the Medan attack, according to the Terrorism Research and Analysis Consortium (TRAC), a think-tank.
But any claim attributed to IS about Wednesday’s suicide attack should be treated with caution, according to Sidney Jones, director of the Jakarta-based Institute for Policy Analysis of Conflict (IPAC).
“We have to be careful about such claims. In the past, when ISIS made claims, we could believe them. But in the past six months, they have claimed things that had nothing to do with them,” Jones told BenarNews, referring to the Islamic State group.
Authorities in Indonesia and elsewhere in Southeast Asia had warned of potential terrorist attacks to avenge the death of the top IS leader, Abu Bakr al-Baghdadi. He killed himself and three of his children by detonating a suicide vest during a raid by U.S. forces in northwest Syria last month.
Also on Thursday, the national police said they had arrested 10 suspected militants during raids mounted in Sumatra and Java island between Saturday and Wednesday. The suspects were members of JAD, including four who had returned to Indonesia after serving as IS fighters in Syria and Iraq.
On Friday, however, it was unclear whether any of those 10 suspects were among the 19 arrested as part of the dragnet into the Medan attack, or whether any were linked to the Medan bombing.
It took place a month after two suspected IS-linked militants stabbed and wounded then-Security Minister Wiranto and two other people as he was visiting Banten province.
Indonesia, the world’s largest Muslim-majority country, has been hit by a string of terrorist attacks in the past two decades, with more recent strikes being blamed on JAD militants.