Last week's deadly attacks in Jakarta could mark the start of a violent campaign by the Islamic State in Iraq and Syria (ISIS) in South-east Asia unless more is done to counter the group, experts have warned.
ISIS has claimed responsibility for the gun and bomb attacks that ripped through a busy commercial district of the Indonesian capital, leaving four civilians dead and more than 20 injured.
It could have been a lot bloodier, said Dr Rohan Gunaratna, head of the International Centre for Political Violence and Terrorism Research in Singapore, if Indonesian security forces had not arrested more than a dozen militants over the past two months, dismantling two terror cells in the process.
Still, ISIS' tentacles are spreading.
As the world's most populous Muslim-majority country, Indonesia seems the likeliest place for ISIS to try to establish a satellite province of its so-called caliphate, a foothold from which to expand its influence from its heart in the Middle East.
As the world's most populous Muslim-majority country, Indonesia seems the likeliest place for ISIS to try to establish a satellite province of its so-called caliphate, a foothold from which to expand its influencefrom its heart in the Middle East.
Already, Indonesia's most-wanted terrorist, Santoso, has pledged his East Indonesia Mujahidin group , which operates in Central Sulawesi, to ISIS' cause. The terror group has also established links with militants in East Java, Lampung in Sumatra, South Sulawesi and West Sulawesi.
"There are 22 groups in Indonesia that have pledged allegiance to Abu Bakr al-Baghdadi," said Dr Gunaratna, referring to ISIS' self-styled caliph.
"As long as those groups exist, there will be extremism not just in Indonesia, but also in the region."
ISIS' influence in the Philippines is also growing, with some experts going so far as to say that the authorities have no time to waste.
After a year-long discussion between local terror groups that had pledged allegiance to ISIS, Abu Sayyaf leader Isnilon Hapilon was chosen to head ISIS in the Philippines, according to Dr Gunaratna.
He believes the Philippine military should deploy itself in the country's south now to nip the situation in the bud before it escalates. He said: "Our assessment is that ISIS will declare a satellite state in South-east Asia, and it could be a combination of elements in the Philippines and Indonesia, or it could be first in the Philippines, then in Indonesia."
Closer to Singapore, Malaysia is also grappling with the spread of ISIS ideology, said Associate Professor Kumar Ramakrishna, head of policy studies at the S. Rajaratnam School of International Studies.
This has even taken root within its military. Last October, two 28-year-olds were arrested at a special forces camp in Malacca for trying to spread ISIS ideology among soldiers. They are among at least 13 military personnel who have been arrested for suspected links to ISIS, according to Malaysian police.
"On top of that, ISIS has an Indonesian and Malaysian unit of fighters - the Katibah Nusantara - in Syria, and these people will come back one day, perhaps sooner rather than later," said Dr Ramakrishna.
The Katibah Nusantara is said to comprise about 700 fighters from Indonesia and 200 from Malaysia.
ISIS' ability to mount more devastating and coordinated urban terror attacks in this region will be strengthened as more of such trained, hardened fighters return to their home countries.
Despite its distance from the Middle East, South-east Asia is a coveted prize for ISIS, and its efforts here show that.
It is not hard to see why - the region is home to a quarter of the world's 1.6 billion Muslims, noted Dr Ramakrishna. "South-east Asia is a natural 'strategic reserve' for ISIS in that sense. Also, the region straddles important sea lanes of communication that are vital to world trade," he said.
Establishing a foothold in the region would allow ISIS to "mobilise, radicalise and militarise a segment of the Muslim community", said Dr Gunaratna.
He said: "The Middle East is too far, but an entity (in South-east Asia) can be a hub for groups to come to for training, strategy and funding... that's why this must be prevented."