Police display documents they seized during the arrest of three suspected Islamic State sympathizers in Malang, East Java, on Wednesday. (AFP Photo/Aman Rochman)

Jakarta/Malang. Indonesia's counterterrorism agency has urged the government to revise laws governing freedom of assembly and speech in a bid to tackle supporters of the extremist group Islamic State.

Insp. Gen. Arief Dharmawan, the deputy for law enforcement and skills building at the National Counterterrorism Agency (BNPT), said the government must revise the controversial 2013 Mass Organizations Law to prevent the spread of IS ideology.

"We have stated that the mass organizations law must be revised and expanded because it only regulates those mass organizations that are registered," Arief said in Jakarta on Thursday.

"What about those unregistered groups? How to we regulate how they should be disbanded? We need a clear legal basis," he added.

Arief also said the government must consider a revision to the 1998 Freedom of Speech Law.

"Can you imagine if pro-IS people made a speech at a public event like the Car-Free Day and then declared that the government were infidels and killing them should be justified?" Arief said.

The comments are likely to alarm rights groups who fear the recent rush of calls for a more aggressive stance against domestic supporters of IS could led to abuses of powers by the security forces.

The mass organization law came under heavy criticism from the public, NGOs and unions when it was passed in 2013, with many arguing some of its provisions were repressive.

But the BNPT, which has recently expressed frustration about its lack of powers under existing anti-terror laws, says the law does not go far enough.

The law only stipulates administrative sanctions for violators and does not provide monitoring mechanisms for the mass organizations, Arief said.

"This loophole has caused unregistered mass organizations to appear and they openly support IS," he said.

Arief said the West Indonesian Mujahideen (MIB), East Indonesian Mujahideen (MIT) and Jamaah Ansharut Tauhid, among other hard-line Islamic groups, had openly declared their support for IS.

'Existing laws enough'

The BNPT last week called on President Joko Widodo to issue a regulation in lieu of law, or perppu, prohibiting Indonesians from traveling to "conflict-prone" countries such as Syria.

The agency has decried its inability to detain and charge Indonesians suspected of traveling to the Middle East to join the jihadist movement.

But Vice President Jusuf Kalla, known for his controversial remarks, said such a perppu was unnecessary.

"The existing laws are enough. Terrorists are evil doers and evil doers must be punished. Not just IS, anything. We don't need a perppu for that," he said.

But counterterrorism officials have been struggling to level criminal charges against Indonesians joining IS. It is not illegal for Indonesians to travel to countries like Syria and Iraq, or to finance others to travel to or already in said countries.

Terrorism analysts have noted that these homegrown and foreign-trained militants will pose a huge threat to the country if they return.

Indonesia has been a terrorism hotbed since 2000, with most of the major actors returning jihadists who had seen combat action in places like Afghanistan and the Southern Philippines, where Islamic militants have launched an armed rebellion against the government.

Some 500 Indonesians are estimated to have joined IS, according to the BNPT.

Some are believed to have returned home to spread the group's radical ideology in the archipelago.

Depok mall attack

Insp. Gen. Tito Karnavian, a former National Police counterterrorism chief, said Indonesian militants believed to have returned from fighting with IS in Syria are suspected of being behind an attempted chlorine bomb attack at a shopping mall in Depok last month.

The homemade device — made up of several bottles and a detonator — was discovered in the ITC Depok mall, south of Jakarta, after it failed to go off properly.

Police said it was the first such attack ever attempted in Indonesia.

Exposure to chlorine gas causes intense irritation to the eyes, skin and airways, and can be deadly.

IS has been accused of using chlorine before, notably in a Jan. 23 car bomb attack on Kurdish forces in Iraq.

The Syrian regime has also been accused of carrying out chlorine gas attacks.

A police source told the Jakarta Globe earlier this month that all the chemicals used to manufacture the bomb were easily available, and that the perpetrators of the failed attack in Depok may have attempted to produce the nerve agent sarin.

The government has previously expressed concerns over the hundreds of Indonesians fleeing the country to join IS's cause, including 16 citizens arrested by Turkish authorities earlier this month for trying to cross the border to Syria, reportedly to support the militant movement.

Deputy Foreign Minister A.M. Fachir said the Syria-bound group was flown home on Thursday and handed over to the National Police once they arrived in Jakarta.

BNPT deputy Arief said the agency would question the group "to prevent them from rejoining IS once they are in Indonesia."

"Not all will be detained, some will go home but we will question them first. Did they try to go [to Syria] because they wanted to? Were they brainwashed? Were they just following their family? We will scrutinize them because they were mostly children," he said.

Malang arrests

On Wednesday, the police's elite counterterrorism squad arrested two men in the East Java town of Malang for alleged links to Abu Jandal, an Indonesian known to be fighting with IS.

Also known as Salim Mubarok Attamimi, Jandal has appeared in an online video calling for a war against the Indonesian security forces and for other Indonesians to join in the campaign to carve out a caliphate in the Middle East.

One of those arrested in Malang, identified as Abdul Helmi Alamuddin, 51, is alleged to have had a role in either making or distributing the video featuring Abu Jandal, also a Malang native.

Meanwhile Abdul Hakim Munabari, 45, is said by police to have recently returned to Indonesia after having joined IS with Abu Jandal.

"Abdul just got back from Syria," Comr. Gen. Badrodin Haiti, the National Police deputy chief, said on Wednesday.

"We will begin to question him. We will do all we can to prevent IS ideology from spreading in Indonesia."

The third to be arrested is a man named Junaedi, or Abu Salman, although his role remains unclear.

National Police spokesman Sr. Comr. Rikwanto said only that Junaedi was responsible "for ensuring Abu Jandal made it to Syria."

East Java Police chief Insp. Gen. Anas Yusuf said all three "lived in Syria for around six months before returning to Indonesia."

During their stay in Syria, Anas said, the three acquired combat and bomb-making skills.

Pro-terrorism content

The government has recently begun working with information technology companies such as Google to block websites with terrorist content.

Indonesians were recently shocked by a video that appeared to show Indonesian-speaking children training with assault rifles in front of an IS flag. The video has since been removed from a number of sites, including Google-owned YouTube.

Communications and Information Technology Minister Rudiantara said on Thursday that the partnerships had enabled the government to remove 78 Indonesian sites with pro-terrorism content.

"Most of the sites were blogs, and after we reviewed them, we saw that they could teach a lot about Islamic radicalism," he said.

"We have worked together with the BNPT and many religious figures," the minister continued.

Rudiantara also confirmed remarks made by his predecessor, Tifatul Sembiring, that identifying such sites were harder than those with pornographic content.

During his administration, Tifatul, a politician from the Prosperous Justice Party (PKS), a conservative Islamic-based party, was criticized for focusing too much on blocking porn sites and doing little to block sites containing messages of hate, religious intolerance and radicalism.

Rudiantara said that unlike porn sites, pro-radicalism sites rarely used predictable keywords, which made them hard to identify through search engines like Google.

Recruitment drive

But IS sympathizers are also resorting to pamphlets and persuasion to look for fresh recruits, officials said, reaching as far as Indonesians working overseas.

Rafail Walangitan, the Indonesian consul general in Hong Kong, said brochures had been distributed to Indonesian migrant workers there calling on them to join IS.

Consulate staff also found brochures inviting Indonesian workers to a sermon hosted by two clerics slated for earlier this week. The clerics were denied entry by Hong Kong authorities.

"Maybe immigration here see [the two pamphlets] as related," Rafail said. "We don't know. [Hong Kong] immigration never told us why [the two were denied entry]."

Earlier, local newspaper Oriental Daily reported that a number of Indonesian workers had also received brochures with an unspecified job offer. The brochures depict a woman draped in black Islamic attire and veil while carrying an IS flag.

Back in East Java, meanwhile, the three suspects in Malang are accused by police of luring dozens of people — mostly impoverished farm workers — to join IS with the promise of cash.

"Some were promised $100 all the way $500," provincial police chief Anas said.

They were also promised bonuses for killing enemies or blowing up a target. "But these promises were never honored."

One of the suspects, Anas said, used a religious school he once managed as a recruiting ground.

"We suspect that he has sent at least 18 Indonesians to Syria," he said.