Warning that the JI is still active in the South-east Asian region, the Deputy Prime Minister said: 'We must be alert for signs that they and other radical groups are stepping up their recruitment efforts or militant activities.'
'If they think that governments are preoccupied with elections and the global economic crisis, and would not pay attention to security issues, they may then try to capitalise on it to gain more ground,' he added, in a reference to recent elections in Malaysia and Indonesia.
Mr Wong, who is also Home Affairs Minister, noted that he first made this point when he spoke at the Internal Security Department (ISD) staff promotion dinner on April 15.
He reiterated it yesterday at a press conference to provide more information on the capture of Mas Selamat by the Malaysian authorities on April 1.
Singaporeans should not think that because Mas Selamat is back in custody, there is no longer a JI threat, he said.
'The JI threat will continue for a long time. If Singapore lets its guard down, we will pay the price.'
This is why officers manning checkpoints - such as the Coast Guard and those from the Immigration and Checkpoints Authority - must continue to be vigilant, he stressed.
He acknowledged however that despite the best efforts of checkpoint guards, people will still manage to slip through, either out of Singapore as Mas Selamat did, or into Singapore as illegal immigrants.
'Singapore is not airtight,' he noted.
On the continuing threat from the JI, he pointed to a core group of five Singaporeans that Mas Selamat had been part of.
Among their members was Mohammad Hassan Saynudin, who was sentenced to 18 years in jail by a Jakarta district court late last month for killing a Christian school teacher and planning terrorist attacks against Westerners in Indonesia.
Information provided by Singapore led to the arrest of Mohammad Hassan in Indonesia in June last year, according to earlier reports.
Leads arising from his interrogation enabled Indonesian police to arrest nine Indonesians and seize more than 20 bombs and 50kg of explosives in raids over the next four days.
Both Mohammad Hassan and Mas Selamat fled Singapore in late 2001 to escape a security dragnet.
They went to Thailand, where they hatched a plan to crash a plane into Changi Airport. This was to retaliate against the December 2001 JI arrests in Singapore and to pressure the United States to stop its attacks on Afghanistan.
They aborted the plot after it was leaked to the authorities.
Yesterday, Mr Wong said: 'ISD has been working on this group. There could be others not arrested.'
He did not give more details.
Noting the close ties between intelligence agencies in the region, he said: 'The cooperation is excellent, and this makes the country and region a safer place for all of us.'
LONG-TERM THREAT
'The JI threat will continue for a long time. If Singapore lets its guard down, we will pay the price.'
DPM Wong Kan Seng
STAYING ALERT
'We must be alert for signs that they and other radical groups are stepping up their recruitment efforts or militant activities.'
DPM Wong