Counter-terrorism leaders in Indonesia and Malaysia say they are grappling with a growing domestic threat from the Islamic State of Iraq and Syria ( ISIS ).

With their large Muslim populations, together the two countries form prime recruitment ground for the organisation that has terrorised people living in parts of Iraq and Syria under its control.

"For Indonesia, the growth of ISIS is a big concern," Indonesian National Counterterrorism Agency ( BNPT ) chief Ansyaad Mbai told Khabar Southeast Asia. "Before ISIS, terrorism in Indonesia had been weakened. There was no real threat, because most of their networks had already been segregated and lacked funding and leadership."

Indonesians are being recruited into ISIS for jihadist duty in the Middle East, and are undergoing military training inside the archipelago, Ansyaad acknowledged.

"However, we are also concerned about the future, especially when the fighters will return trained in terrorist tactics and demand the establishment of caliphates in the region," he added.

"ISIS does not represent Islam"

ISIS is also a problem for Malaysia, which welcomes co-operative opportunities with other countries in the region or beyond to deal with the threat, said Ayob Khan Mydin , the Royal Malaysian Police (RMP)'s deputy chief of counter-terrorism.

"Malaysia has encountered several cases of ISIS jihadists in our own country. We want to ensure that our country is free from the violence. We are also concerned about the massive propaganda over social media," he told Khabar by phone.

Earlier this year, the RMP foiled a plot by ISIS-inspired extremists to mount a wave of bombings in Malaysia. Nineteen suspects were arrested in that plot.

"Malaysia will not tolerate any crime or violence using religion as a justification," Ayob said.

Malaysian police also are scrutinising humanitarian groups as possible covers for home-grown jihadists who are heading to Syria and Iraq, he added.

Two Malaysian jihadists , Mohammad Lofti Ariffin and Mohammad Fadhlan Shahidi, were killed in a September 9th missile strike in Syria.

Prior to those deaths, Malaysian Prime Minister Najib Razak said his government was concerned about citizens waging jihad in Iraq or Syria and would work with the international community to stop ISIS and other radical groups from spreading their influence in Southeast Asia.

"We will work together with the large community, as ISIS does not represent Islam. ISIS is a misnomer. It does not do justice to Islam," Razak said during a joint news conference in Putrajaya with visiting Australian Prime Minister Tony Abbott on September 6th.

Enlisting religious groups

Indonesia is enlisting its mass Muslim organisations for help in blocking the spread of ISIS ideology, according to military commander General Moeldoko.

"Religious leaders play an important role in helping those who have already agreed with ISIS's wrong ideology, and to bring them back to the truth of Islamic teachings," he said. "It is important for our future generations to avoid radicalism."

Muhammadiyah Chairman Din Syamsuddin said it will not hesitate to help curb the explosion of ISIS in Indonesia.

"The government and the community will need to work together to prevent the wrong ideology of ISIS from taking root in the country," Din told Khabar.