SINGAPORE - Security in places of worship here may have to be reviewed to protect worshippers in the light of increased risks, but these places must remain welcoming and cannot be turned into fortresses, said Law and Home Affairs Minister K. Shanmugam.

And as the threat of attacks from self-radicalised lone wolves is ever present, community vigilance and partnerships remain an important tool to protect Singapore, the minister said on Wednesday (March 10).

He was speaking to reporters at Maghain Aboth Synagogue in Waterloo Street, shortly before the Internal Security Department (ISD) announced that a 20-year-old Singaporean man had been detained for making plans to kill Jews leaving the synagogue.

On Wednesday morning, Mr Shanmugam joined Muslim community leaders on a visit to the synagogue to show solidarity with Jewish community leaders, and affirm that the thwarted attack would not harm the strong bonds between the leaders and the harmonious relationship among various communities.

He was also asked about the need to beef up security at religious sites here, given how there have been two reported cases of thwarted terror attacks on places of worship of late.

The latest development comes weeks after the ISD announced in late January that a 16-year-old self-radicalised student had been detained for planning to attack two mosques in Sembawang and Woodlands.

Said Mr Shanmugam: "I think the security measures may have to be stepped up a bit to balance off the risks that are increasing... it has to depend on how the threats evolve.

"But my own sense is that not all religious sites will have to be protected to the same level, some face a higher threat level and they may have to take some additional measures," he said.

The minister stressed the need for balance, noting that while religious sites do have to have some level of security, they have to look and feel like places of worship.

"When you walk into a synagogue or a church or a temple or a mosque, how would you feel if the place looks like a fortress, a cantonment with armed guards patrolling it? Is that how we want to turn our places of worship into?" said Mr Shanmugam.

"I think there needs to be some level of security. And depending on the perception of threat, there may have to be some guards inside. But we need to be very, very careful how we do it," he added.

The Government has some clear ideas about how such sites should be protected, and the broad approach has got to be that different religious sites carry different threat levels, he said.

Mr Shanmugam added that there may be differences in the way they are protected according to these varied threats, and the authorities will work with different sites to alert them on what security measures they need to have. Some might require more hardware and some might need to place guards to patrol in a more discreet way.

The Government is also constantly watchful of the security threats that Singapore faces, and the minister pointed out that the ISD is always on the look out for cases of people who wish to stage attacks here and disrupt Singapore's harmony.

Mr Shanmugam also underscored the critical role that community members play in preventing terror attacks from happening here, noting that although the ISD has built up its capacity to pick up signs of self-radicalisation, this can never be perfect.

"It is an ever-present risk. It's going to require the community to be vigilant, the family to help. So far, many of these cases have come to light because the family has told us (and) friends have told us," he added.

Chief Rabbi Mordechai Abergel told reporters the Maghain Aboth Synagogue is in the midst of upgrading its security facilities, like the guardhouse at the entrance, and is looking to invest in tools like surveillance equipment.

But as the synagogue makes these adjustments to keep its worshippers safe, Rabbi Abergel said it is mindful not to cause any alarm.

"We're making it clear that we'll do everything we can to provide all the security measures to keep our congregants safe and secure within our premises, but by the same token not to blow things out of proportion," he said.