Malaysia's police chief Khalid Abu Bakar on Friday said there were unconfirmed reports of "imminent terrorist threats" in Kuala Lumpur, where the 27th Asean summit got underway in Kuala Lumpur.
So Malaysian officials deployed additional security to secure the summit.
In all some 4,500 troops were said to be either deployed or on standby.
There have been real security concerns in the region, according to Monica Schael-Isenor, a Canadian living in Kuala Lumpur.
"They [the Malaysian police] have arrested 150 terrorist suspects in Malaysia in the last couple of years, since 2013, and they are trying to make immigration into the country more difficult," she told RFI. "So there are things being done. There were also bombs that were supposed to be detonated in September in a vibrant tourist area called Bukit Bintang and the Malaysian police managed to prevent that from happening. So that was kind of scary, for sure."
Like Manila's Apec summit, this weekend's Asean summit is largely meant to focus on the economy. In Asia, peace is a question of prosperity. The issue of terrorism, however, did come up during the Apec summit in the Philippine capital, Manila. It even appeared in the summit's final statement.
"It's interesting you know, that within the context of that recent Apec statement, it says, sure, terrorism is to be condemned. But the principal rationale it gave for that, the reason for condemning terrorism, is that it sees this as a threat to free and open economies," comments William Case, a professor of comparative politics at City University of Hong Kong.
"That tells us a lot about what the priorities are of countries within the region."
The summit in Kuala Lumpur was to include a meeting of Asean's political security committee, which is primarily tasked with solving intra-regional conflict.
The threat posed by terrorists - and by the Islamic State (IS) armed group in particular - will affect the Asia-Pacific region, warned Rohan Gunaratna of the International Centre for Political Violence and Terrorism Research at the S Rajaratnam School of International Studies in Singapore.
"The Syrian conflict has a blowback which is global because to fight in Syria, more than 15,000 youths went from Asia, Africa, Middle East, North Africa and Europe," he said. "So those youths who went to Syria to fight, now they will go back to their own countries to mount attacks around the world."
Asian countries have a particular challenge because, with so many people passing through their borders by land or often by sea, authorities find it hard to distinguish amongst economic migrants, potential refugees and smugglers, he explained.
Asean leaders must do a better job of making the right distinctions, Amnesty International’s Interim Director for South East Asia and Pacific, Champa Patel, believes.
"Often terrorism is the reason that they [refugees] have left their countries of origin, from those kinds of security concerns," she told RFI. "And I think it is unhelpful to conflate the two issues, because I think what it does is criminalise people who have had no choice but to leave their homes."