Singapore sees a "clear and present danger" to Asia from Islamist militancy, especially from the threat of groups linking up after pledging allegiance to Islamic State, its defense minister Ng Eng Hen said on Wednesday.
A day after signing a defense cooperation agreement with the United States that covers trans-national militancy, Ng said intelligence sharing was key to dealing with the issue.
"We see the threat of extremist terrorism as a clear and present danger in our region," he told a Washington seminar.
Ng said that in the past three years the numbers of Islamic State sympathizers had exceeded the number of supporters al-Qaida had in the 10 years in which it was influential.
He said Singapore's neighbor Indonesia had reported that more than 500 of its citizens had gone as foreign fighters to Syria and Iraq and as many as 150 had gone from Malaysia, including some from the armed forces. A handful had also gone from Singapore, he said.
"And the returned fighters have come back and pledged allegiance to ISIS and the mission to form an Islamic caliphate in our part of the world," Ng said.
"They have sympathizers; they have foreign fighters who have been trained, have the motivation and the means, and who have a common vision. And so we look at this threat very carefully."
Ng said members of Jemaah Islamiyah (JI), an al Qaeda offshoot that planned bomb attacks in Singapore in the early 2000s, had pledged allegiance to ISIS, as well as the Abu Sayyaf group in the Philippines.
"Many of those who we were arrested who are JI, who were operatives in JI, are still around and they are going to be released from detention and they have already linked up JI cells," he said.
"So the danger is a link up formalizing of these loose groups into a force that will threaten our security and well-being."
Australian Justice Minister Michael Keenan said in Singapore earlier on Wednesday that Australia and Southeast Asia must re-double efforts to share intelligence and make sure Paris-style attacks cannot be replicated in the region.
Islamic State last year captured parts of Syria and Iraq, and declared the creation of a caliphate, or state, governed by its hardline interpretation of Islam. The group has since made claims to violence outside its domain, including last month's deadly Paris attacks that killed 130 people.