From India to Indonesia to the Philippines and across South East Asia, the Islamic State (ISIS) is creating a presence through “family terror cells” in the region after recent defeats in Iraq and Syria, where it ruled thousands of square miles of territory.

The ISIS call to establish a pure "Islamic environment" continues to attract Asian followers, sweeping up whole families in the process -- rich and poor alike said a South Asian intelligence operative told Nikkei Asian.

"This family phenomenon has a lot to do with the ideology of the IS caliphate," said the operative. "It was an appeal to radicalized Muslims to live as true Muslims and enjoy a perfect Islamic life, which is a shift from [al-Qaida] since it never talked of creating a caliphate."

Considered a terrorist group by the western world, ISIS recently announced the formation of bases in nuclear-armed India and Pakistan, two arch-rivals that fought three wars since their independence from Britain in 1947.

According to the ISIS-affiliated Amaq News Agency, the terror organization on May 11 officially proclaimed the existence of “Waliyah of Hind,” or India Province. Shortly afterward, on May 15, ISIS said it had established an additional stronghold called “Wilayah Pakistan.”

“ISIS has been looking for new ventures after it was defeated in Iraq and Syria. Even in Afghanistan, things are not in ISIS’s favor," Rashid Hussain, a Rawalpindi-based security expert, told The Media Line.

"It is now trying its luck in Pakistan, India and Sri Lanka, where it already has been outsourcing attacks.”

At its peak, IS controlled significant swaths of war-torn Iraq and Syria. But over the last five years, it has lost almost all the territory where it had planned to build its caliphate. The group staked a claim in Mindanao in the southern Philippines — Southeast Asia's largest Catholic country — for the caliphate in 2017, raising fears over a largely Muslim area already gripped by a nearly four-decade civil war that has cost more than 120,000 lives.

In Sri Lanka, ISIS claimed responsibility for last month's series of Easter Sunday bombings in the capital Colombo that killed 290 people and wounded 500 others. Several wealthy and influential local families were involved.

In mid-March, the wife of a jihadi cell leader triggered a bomb in North Sumatra, Indonesia, the world's most populous Muslim country. The explosion destroyed an entire neighborhood.

In late January, an Indonesian husband and wife carried out a suicide attack on a church in the Philippines, killing 20 and wounding 102.

Back in May of last year, families — four children aged 9 to 18 and their parents — targeted churches in Surabaya, Indonesia's second-largest city. At the time, Indonesia-based analysts described the attack as "unprecedented," since parents were taking their children "to blow themselves up."

The more active role of women marks a notable shift, according to the Jakarta-based Institute for Policy Analysis of Conflict.

"From the beginning, they played important roles [in IS networks] as teachers, couriers, propagandists and financiers. But in the new decentralized ISIS world, they are playing combat roles as well," the independent think tank noted in a report in April, using the alternative acronym for the group also known as Islamic State of Iraq and Syria.

Counterterrorism operatives in Malaysia agree. The country's Special Branch, an intelligence unit, has noticed how women are moving from "supporting roles to front-line roles," said a Malaysian national security source. Alarm bells went off after a 51-year-old woman was arrested for plotting to pack her car with gas cylinders and crash it into voters at a polling station during the country's general election in May 2018.

Kuala Lumpur believes over 100 Malaysians, women among them, left the country to bolster the IS ranks in the wake of the group's dramatic rise in 2014. Jakarta estimates that over 500 Indonesian did likewise, while Colombo's estimate is 32, including some entire families. But the vision of a Middle Eastern caliphate has gone up in the smoke left by U.S.-led military strikes.

India faces the same worries about returning fighters. The southern state of Kerala became fertile ground for recruitment: Over 20 affluent, well-educated men and their families left to join IS in 2016. Some were doctors and engineers, while others had business degrees.

The Muslim-majority Maldives, which has a population of 400,000, saw somewhere between 250 and 450 leave to join the movement. That made the necklace of islands, better known for idyllic resorts, the largest supplier of IS recruits per capita. The volunteers included 61 men who took their wives and children through Turkey to IS camps in Syria, according to the country's counterterrorism body.

Seasoned observers also link the spike in Islamist extremism in Asia to the proliferation of the Wahhabi and Salafi ideologies since the 1980s. Propagated by Saudi Arabia, these strains of Islam have been blamed for promoting intolerance that has spawned terrorist networks including al-Qaida and IS. And they have seeped into Asian communities that had practiced more moderate forms of the religion.

Explosives experts, meanwhile, see another troubling connection between mushrooming IS cells in Asia: the materials they use.

The Easter bombers used TATP, or triacetone triperoxide — a substance al-Qaida dubbed the "Mother of Satan" for its destructive power. The same explosive was used in the bombings in Indonesia this past March and in May of last year.

"TATP has become a popular explosive among terrorist groups because you can get the basic material from hardware stores and supermarkets," said Phill Hynes, the lead terrorism expert at ISS Risk, a Hong Kong-based security consultancy. "You don't have to go to Syria or Iraq to learn bomb-making skills."

Experts say investigators must get to the bottom of the Sri Lanka bombings fast. Before the attacks, the South Asian country had barely registered on the radar of new IS frontiers. Now it is seen as an indication of what IS-inspired networks are plotting.

Ethnic tensions in countries like Sri Lanka only add to the volatile mix. The Easter attacks triggered an anti-Muslim backlash, but analysts caution this could simply fuel further radicalization.

Hynes said extremists could try to take advantage of local grievances, "exacerbating them and turning them into rallying points or touchstones for the IS trend in Asia."