SINGAPORE - Coils of concertina wire have been put up to deter other trespassers near the spot where a man who climbed onto the MRT tracks last Thursday (Feb 25) was killed.

The extra precaution, about 150m from Kallang MRT station, is in addition to other fences and barbed wire already in place in the area.

The concertina wires beef up security at a part of the overground track where elevated fields, scalable features on the viaduct and the proximity of a footpath to the track make it especially vulnerable to intruders.

No details have been made available on how the 31-year-old man who died last Thursday accessed the tracks, or whether he was spotted on any of the closed circuit television cameras.

The Straits Times understands that he found his way into the eastbound tunnel between Lavender and Kallang MRT stations, accessing the tunnel via a portal area where the train tracks enter the underground tunnel from an overground position.

This is a short walk from where the concertina wires have been set up, near where the body was eventually found.

Last Thursday night's incident caused a disruption on the East-West Line between Bugis and Aljunied MRT stations, and raises questions about whether more could be done to protect MRT tracks - and the system - from intruders who could cripple train service for hours.

After the alert was sounded last Thursday at 9.35pm, Lavender and Kallang MRT stations had to be closed for the day.

Mr Ikhsan Suri, the executive director of the Security Association Singapore, said there had been very few platform-related fatal incidents since platform screen doors were installed on the MRT lines.

The North-South and East-West lines, for example, were retrofitted with half-height platform screen doors between 2009 and 2012.

He added: "Perhaps what can be done further is to continue to review and update the security and safety risks all along the train system and infrastructure.

"Technology such as smart sensors or video analytics deployed alongside an expanded CCTV network could be leveraged to reduce the chances of such tragic accidents from happening in the first place, and also shorten the response time for emergency services in such incidents."

Last Thursday's incident was the first MRT track fatality since two SMRT trainees were knocked down by a train in March 2016. A year later, in March 2017, another track death occurred on the Bukit Panjang LRT after someone who was drunk got onto the tracks near Fajar Station, was hit by a train and died.

LRT stations have also been fitted with similar platform screen doors since 2015, although these do not have sliding doors but have fixed openings with which trains align their doors.

Mr Ikhsan cautioned that it would be a "herculean task to keep out the most determined intruders", and that security provisions must be balanced with cost.

"Nonetheless, every accident must be treated as avoidable," he said.

Since 2015, the Land Transport Authority has erected anti-climb barriers to prevent such incidents from paralysing the train network. The Redhill MRT Station tunnel portal, for instance, has a 3m-high fence topped with razor blades.

The police have said they do not suspect foul play in the latest incident. Investigations are continuing.