Terrorists have already had one of Singapore's own train stations in their sights.
In January 2002, the authorities revealed that Yishun MRT station had been the target of a bomb plot by a terrorist cell here.
The unnerving revelation came just months after 9/11, and underpinned an urgent need to bolster the security of "soft targets" such as train stations and bus interchanges.
This was further driven home by an attack in Madrid in March 2004, during which 10 coordinated explosions claimed the lives of 191 railway passengers.
The very next month, Singapore formed the Public Transport Security Committee, a multi- agency body which reviews the security arrangements of the public transport system, and recommends and oversees improvements.
A chilling reminder of its important role came in July the following year, when suicide bombers targeted underground trains and a bus in London, killing 52.
Indeed, the next month here, a dedicated Police MRT Unit was introduced to step up the police presence.
This unit was upgraded four years later into a full division, the Public Transport Security Command.
Public transport operators (PTOs) SMRT and SBS Transit also started employing their own security staff, whose roles include conducting bag checks.
Surveillance cameras are now in place at all MRT and LRT stations and bus interchanges. Bins and postboxes - into which incendiary items could be dropped - were moved out of the vicinity.
Public awareness has been heightened as well, through regular announcements to tell commuters to look out for suspicious items left behind by others.
"Commuters can play an important role in our security efforts," says Ms Tammy Tan, senior vice-president of corporate communications at SBS Transit.
However, confidence in the security of the transport network was shaken in May 2010, when two vandals cut through the fencing at SMRT's Changi depot and spray-painted a train.
In August 2011, a similar incident was repeated at the Bishan depot.
Security at train and bus depots has since been beefed up, through the deployment of more patrols and security personnel, and the installation of fence intrusion-detection systems.
But it appears that more needs to be done. In November last year, two German nationals allegedly breached the Bishan depot and vandalised a train.
Investigations are ongoing and the Land Transport Authority (LTA) has conducted a detailed site survey with SMRT and other government agencies.
In LTA's announcement of higher rail service standards on Thursday, security was not left out. PTOs will have to ensure that their video surveillance systems meet a certain level of reliability.
Mr T. Mogan, security director of consultants Dragnet, points out that all security systems require constant refinement, through regular audits and reviews.
This article was first published on Jan 17, 2015.
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