SINGAPORE - Singaporeans need to reach out to each other across racial lines and build bonds between communities, in order for society to rally together in the aftermath of a terror attack here.

Home Affairs and Law Minister K. Shanmugam said this on Tuesday (June 13), adding that community leaders have a role to play in promoting this.

"We have to reach out to each other across communal, racial lines. We can be a good Muslim, good Hindu, good Christian, or completely agnostic. At the same time, we can be good Singaporeans interacting with each other," he said.

He was speaking to reporters at the Home Team Academy Workplan Seminar, held at the Immigration and Checkpoints Authority headquarters.

Asked if Singaporeans would rally together after a terror attack as communities have done in Paris and London, he said: "My own sense is that by and large, Singaporeans understand that any act are of isolated extremists and based on that, I think we will react as a community."

In his speech to Home Team officers earlier, Mr Shanmugam flagged terrorism as the top security threat facing Singapore.

Many of the attacks worldwide were being carried out by lone wolves, who can strike at any time and place, he noted.

And such attacks, while less sophisticated, are more difficult to predict.

Officers have to be trained to respond to an attack that happen suddenly with little or no warning, he said.

His remarks come a day after the Ministry of Home Affairs released details of the first Singaporean woman detained for radicalism under the Internal Security Act (ISA).

Syaikhah Izzah Zahrah Al Ansari, 22, was a contract infant care assistant with a PCF Sparkletots Preschool.

She had begun to be radicalised in 2013 by online propaganda from terror group the Islamic State in Iraq and Syria (ISIS), and had been planning to travel to Syria with her young child.

There, she harboured thoughts of marrying an ISIS fighter and becoming a "martyr's widow", believing she would reap "heavenly rewards" if her husband died in battle.

Her parents, who were Quranic teachers, and sister had known of her radicalism in 2015, but did not alert the authorities. One family member even destroyed evidence relating to Izzah's plans to travel to Syria when she was under investigation - in a bid to minimise the seriousness of her crimes.

The MHA had pointed to the case as an example of how early intervention by the authorities could have diverted Izzah from her eventual radicalisation.