Dozens of Indonesians who joined Islamic State in Syria have returned home with combat experience and pose a major threat to the world’s biggest Muslim-majority nation, the police chief said on Monday.

 

Authorities are closely monitoring about 40 returnees and are concerned they could be linking up with existing networks to equip a new generation of radicals with the skills and equipment required to launch a major attack.

 

"We are getting in touch with them but they can evade our detection. We believe they are organizing secretly and building interactions with other (radical) networks,” police chief Tito Karnavian told Reuters in an interview.

 

About 10 were in custody for questioning and the rest remained free, Karnavian said, adding there was no evidence of an imminent attack.

 

The vast majority of Indonesia’s 250 million people practise a moderate form of Islam. Small extremist groups that have periodically mounted attacks against the state and foreigners in the country have been largely disbanded or driven underground.

 

But the country has seen a recent resurgence in militancy, inspired in part by Islamic State. Authorities believe Islamic State has more than 1,200 followers in Indonesia and nearly 400 Indonesians have left to join the group in Syria.

 

Indonesia suffered its first militant attack in years in January, when four pro-Islamic State militants launched a gun and bomb attack in the heart of the capital Jakarta. Eight people were killed, including the attackers themselves. Authorities said the assault was poorly planned and executed.

 

Karnavian also said a worrying new trend was emerging of teens being radicalized online and lured into carrying out small-scale attacks.

 

A 16-year-old in August tried but failed to detonate a homemade bomb in a church in the northern city of Medan. The teen also tried to stab the priest leading the service but was subdued by members of the congregation. Authorities said the teen was obsessed with Islamic State leader Abu Bakr al-Baghdadi and had researched his ideology online.

 

“This is a new trend. It’s more difficult (to track them) than existing networks...because they are what are called lone wolves that are being radicalized online,” Karnavian said, adding police were aware of at least 10 such cases.

 

Under anti-terrorism laws, police can detain suspects for questioning for up to seven days. The government has called for preventive detention and the stripping of known militants of their citizenship if they fight for extremist groups overseas.

 

Revisions to the anti-terrorism bill are pending parliamentary approval.