The ministry said it had deported 16 other radicalised foreign domestic workers since 2015 but had not issued detainment orders in those cases.

“The government takes a serious view of any form of support for terrorism in Singapore – whether by Singaporeans or foreigners,” it said. “The public should exercise caution against viewing radical material online, including sermons by extremist preachers.”

“In the past, for individuals to join a terrorist group, you’d have to join a specific group offline, either through religious gatherings or Islamic schools,” said Noor Huda Ismail, a visiting fellow at Nanyang Technological University’s S. Rajaratnam School of International Studies (RSIS).

“But now, terrorists are moving away from collective action to connective one. We are seeing a number of people who went online and suddenly show their support [for terrorists].”

According to the MHA, the three domestic workers became convinced that Isis was fighting for Islam and that its use of violence against ‘infidels’ was justified.

“Their radicalisation deepened after they joined multiple pro-ISIS social media chat groups and channels,” the ministry said.

The trio also became acquainted and later developed “pro-militant foreign online contacts, including ‘online boyfriends’, who shared their pro-Isis ideology”.

The MHA said Anindia and Retno had plans to join the extremist group in Syria, while Anindia was “prepared to take up arms for Isis … and become a suicide bomber”.

“They also donated funds to overseas-based entities for terrorism-related purposes, such as to support the activities of Isis and [Indonesian terrorist group Jamaah Ansharud Daulah]. [One] believed that her donations would earn her a place in paradise,” it said.

On September 16, a 34-year-old Singaporean man, who had been similarly radicalised and wanted to undertake armed violence in support of Isis, was charged for “providing money for terrorist purposes”.

Investigations later revealed the man had provided S$1,145 (US$830) to an individual overseas who was facilitating terrorist acts.

THE FIGHT AGAINST TERROR

Like the three domestic workers, he was held under Singapore’s Internal Security Act (ISA), which allows for preventive detention without trial to ensure the country’s safety.

Under the ISA, those deemed to be radicalised are arrested and detained or placed under orders that restrict their movement. Singapore’s law and home affairs minister K. Shanmugam has described it as the single most important tool against terrorism.

If convicted, those who provide “property and services” for terrorist purposes can be jailed up to 10 years and fined up to S$500,000 (US$362,827). They would also be held separately to prevent them spreading radical ideas to other inmates, while undergoing rehabilitation.

Southeast Asia has continued to be a breeding ground for Isis’ brand of militant Islam, despite its self-declared caliphate in Syria and Iraq being broken up by United States-backed forces earlier this year.

Analysts Zachary Abuza and Colin P. Clarke recently wrote in Foreign Affairs magazine that Isis is moving towards a decentralised model of global insurgency. Sympathisers and fighters have flocked to the Philippines, Indonesia and Malaysia, sparking concern among authorities in the region.

The militant group has drawn thousands of women across the world, with many told that by marrying a fighter and raising children they would be part of building a new Islamic world order.

Faizal Abdul Rahman, a research fellow at RSIS, said women had been a target of Isis recruitment in Europe, Middle East and Asia since 2014.

In Singapore, mosques and the Religious Rehabilitation Group have been conducting courses to tackle the threat of radicalisation among domestic workers.

On September 22, about 250 domestic helpers took part in a dialogue and a documentary screening aimed at correcting misinterpretations of Islamic concepts.

The film, Pengantin, examines the lives of three Indonesian maids looking for love, two of whom were eventually jailed for terrorism-related activities.

It was directed and produced by Noor Huda from RSIS, who said the rise in radicalised domestic workers was expected, while noting that they were a vulnerable group as they were away from home.

“Some of them are marginalised even before they work abroad … they do not have good education and are economically weak,” he said.

Noor Huda explained that in some instances, a lack of understanding between employers and domestic workers forced the latter to turn to social media for support – where they were at risk of being radicalised.

His documentary also looks to shed light on the importance of not learning religion in a purely online environment.

“You need context to understand what you're seeing online. It’s better to go to the mosque and ask teachers about Islam, rather than picking them up through social media alone. It's an echo chamber,” said Noor Huda, who added that more needs to be done to prevent a growth in such cases.

Employers should build a “meaningful relationship” with their domestic helpers, he said, explaining that this would help build a community in which domestic workers were comfortable, and facilitate the sharing of views and concerns.

Faizal, meanwhile, suggested employers share news with their domestic helpers to keep them better informed.

“Showing compassion and understanding to domestic workers goes a long way in showing that we live in a just and peaceful society that is better than the realm of war that Isis offers,” he said.

Muslim organisations could widen their efforts to reach more foreign domestic helpers with their programmes, he said.

Noor Huda said domestic worker agencies should also be involved, including providing digital literacy lessons on top of helping helpers understand cultural differences between Singapore and their home nations.

Faizal warned, however, that Monday’s detention of domestic helpers should not alarm employers.

“Employers must not overreact as domestic helpers, like anyone else, are targeted by Isis recruiters,” he said.

“Regardless of nationality, radicalised helpers and radicalised Singaporeans are equally a concern if they intend to conduct attacks. Both domestic helpers and Singaporeans must be protected from the dangers of radicalisation.”