It was yet another case of an individual getting self-radicalised and family members and friends doing nothing about it. But people who are seduced by extremist ideology may not grow out of it, Dr Yaacob Ibrahim, Minister-in-charge of Muslim Affairs, said yesterday.
Their family members and friends also cannot merely hope that they will snap out of radicalisation and do nothing, he added.
"We cannot take the threat of radicalisation lightly, and merely hope that someone can grow out of it," Dr Yaacob, who is also Minister for Communications and Information, said in a Facebook post.
The Ministry of Home Affairs (MHA) announced yesterday that it had arrested two auxiliary police officers for terrorism-related offences last month.
One of them, Muhammad Khairul Mohamed, 24, has since been detained under the Internal Security Act for planning to travel to Syria to fight against the Syrian government.
The ministry said that "several relatives and friends knew of his intention to fight in Syria, but none of them came forward".
Last week, the ministry also revealed that it had detained Syaikhah Izzah Zahrah Al Ansari, a 22-year-old infant care assistant, who was planning to travel to Syria with her child to become a "martyr's widow".
The MHA had said that her family members, too, did not report her to the authorities.
The news of the arrests yesterday again prompted calls on the need for families and friends to report those they suspect of being radicalised.
Dr Yaacob said that Khairul's parents and relatives had known about his intentions, but "did not take them seriously".
He added: "The new cases underscore once again the important role of parents, religious teachers and the community at large to look out for each other, and to immediately refer any signs of radicalisation to the Islamic Religious Council of Singapore (Muis), Religious Rehabilitation Group (RRG) or the police.
"This is the best and only way to help a loved one before it is too late," he said.
Law and Home Affairs Minister K. Shanmugam said the family members in Khairul's case had "a very serious responsibility, which they didn't discharge".
"They have to come forward. They are helping the individual, they are helping us, they are helping the country, and we have to urge, and where we think it is necessary, we will take steps," he said after a briefing on the arrests.
"It is not possible for intelligence agencies to know everything that is going on," the minister noted.
Environment and Water Resources Minister Masagos Zulkifli said: "I hope my community will reflect the need to watch out for our children and loved ones. We cannot allow strident or extreme teachings of Islam to take root here."
He wrote on Facebook: "We must not let our guard down and must continue our efforts in tightening processes to detect and guard against terrorism."
Meanwhile, Muis said the Internet is not the right place to receive religious guidance or to understand the "complex political and armed conflicts in the Muslim world".
The best way to help family members is to refer them to experts like those in the RRG when they detect something is amiss, Muis added.