A Malaysian terrorist suspect deported from Turkey to Kuala Lumpur was among 17 people arrested in Interpol’s recent cross border operation to combat terrorism and crime in Southeast Asia.

Interpol, on its website, said Operation Sunbird III involved the police, immigration and maritime authorities of the Association of Southeast Asian Nations (Asean) countries working to screen passports against the international police organisation’s global databases at 35 land, air and sea border points.

Some eight million searches were conducted during the operation from March 28 to April 5, resulting in 17 arrests and the recovery of 110 passports listed in Interpol’s Stolen and Lost Travel Documents (SLTD) database.

An Italian passport listed as an SLTD was intercepted in Bali by Indonesian immigration. It was being used by a Sri Lankan suspected of purchasing the passport in Kuala Lumpur from a criminal organisation.

Funded by the Canadian government, Operation Sunbird III was conducted under the umbrella of Interpol’s Capacity Building and Training unit and Integrated Border Management Task Force, in cooperation with Asean, Aseanopol, and the United Nations.

Interpol Capacity Building and Training director Harold O’Connell said the  purpose of Operation Sunbird III was to improve cooperation between law enforcement agencies to combat the ever-evolving threats arising from terrorism "by equipping the officers with the necessary skills and knowledge."

Operation Sunbird III was the first major activity under Project Sunbird, the second phase of a multi-year programme to develop the counter-terrorism skills of law enforcers in the region.

In the first phase of the programme, which concluded in March, law enforcement, border and immigration agencies, forensic experts, investigators and national decision-makers underwent  specialised training in forensic techniques, counter-terrorism investigative skills and Interpol’s data sharing mechanisms.

One of the project’s priorities is to ensure that police have the necessary policing capabilities, competencies and mechanisms to effectively prevent and investigate crime, with Project Sunbird facilitating secure information sharing among Asean countries on  terrorist fighters travelling in Southeast Asia.

The High Commissioner of Canada to Singapore, Nancy Lynn McDonald, said: “This project builds upon previous Canada-Interpol partnerships focusing on intelligence gathering and criminal analysis in Southeast Asia.

"With the use of new and emerging technologies by terrorists for the purposes of recruitment, radicalisation and training, such as the use of social media, it is even more incumbent upon the law enforcement community to work collaboratively to address these threats.”

The 10 Asean members are Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand and Vietnam.

South-east Asia appears ripe for the taking because of the region's sizeable Muslim population, the success the group has enjoyed so far in winning over sympathisers, and the presence of established radical leaders and militant groups like Abu Sayyaf in the Philippines.

ISIS has ambitions of establishing a caliphate in the region, and is taking targeted steps to court supporters.

It has set up a South-east Asian unit, Katibah Nusantara, which, besides fighting in the frontlines, has produced propaganda videos in Malay and Bahasa Indonesia - featuring Malaysian, Indonesian and Filipino fighters.

A media agency linked to ISIS last year published a Bahasa Indonesia newspaper called Al Fatihin. This was banned in Singapore, with the Ministry for Communications and Information citing the publication's "clear intention to radicalise and recruit South-east Asians to join ISIS".

ISIS has also rallied various militant groups in the region. More than 30 such groups from South-east Asia, mostly from Indonesia, have pledged allegiance or expressed their support for ISIS.

In addition, the return of battle-hardened South-east Asian fighters has raised concerns that they will tap on their experience in Iraq and Syria to mount attacks on home soil.

Singapore, with its status as a financial hub and its participation in the US-led global coalition against ISIS, is a valuable target.

Terror attacks have already rocked Malaysia, Indonesia and the Philippines, and "sooner or later, somebody will break through", said Singapore Prime Minister Lee Hsien Loong last year.

Jasminder Singh, a senior analyst with the International Centre for Political Violence and Terrorism Research at S. Rajaratnam School of International Studies (RSIS), said: “In September we heard Indonesia has 500 plus (fighters), with 40 only being identified.

"So that becomes a problem. And in Indonesia with the two recent demonstrations in Jakarta, there was actually talk on social media that the returnees have taken part in these demonstrations.”

Malaysian authorities said more than 100 Malaysians have joined IS in Syria since 2013. About 20 of them have been killed. At least 50 others want to return home but are unable to because their passports have been revoked or destroyed.

Mindanao in Southern Philippines has been highlighted as one possible location for the returning fighters to regroup.

There, IS has appointed an Emir – Hasilon Apilon – to head the Philippine IS unit, called Khatibah Al-Muhajir. Apilon is a leader of an Abu Sayyaf faction that has pledged allegiance to IS.

This is in addition to Khatibah Nusantara – the IS-wing in Syria and Iraq made up of Southeast Asian fighters. Its leaders include Bahrum Naim from Indonesia and Wanddy from Malaysia. They have allegedly orchestrated the attacks in their respective countries.

“Recruitment will definitely continue. What is the next monster after IS? And we have so many groups. We cannot forget the AlQaeda Jabhat Al-Nusrah, Ajjnat Arsham – (these) were the initial groups the Southeast Asian fighters joined. Would these groups then go back to recruit more fighters for IS?” said Singh.

This would pose a challenge for Southeast Asian governments. To counter terrorism, they must then have in place strong surveillance and a good legislation – and, more importantly, policies to actually tackle and counter these issue that have gained prominence in the region.