The police want to beef up security at both of Singapore's land checkpoints with a new perimeter detection system.

Vendors were invited from March 13 to submit proposals for a Perimeter Intrusion Detection System for the Woodlands and Tuas checkpoints. The system will provide an additional layer of security to existing fencing at the checkpoints.

It must be able to immediately detect and locate any physical intrusion at the checkpoint fences, whether by someone attempting to scale or cut the fence.

It should also be able to detect when and where sensors or electronic parts are being tampered with.

A police spokesman said the new system will improve checkpoint security by pinpointing the location of any attempted intrusion, thus allowing security forces to respond "in a timely manner".

He added that the idea for such an intrusion detection system, which includes the use of CCTV cameras, came from a review in 2012.

The Woodlands checkpoint suffered two recent security breaches, which prompted calls for stronger security measures.

In January, Malaysian teacher Nurul Rohana Ishak, 27, slipped past officers by tailgating a car, and was only arrested three days later.

On March 8, permanent resident Tan Chu Seng, 64, drove his car over a security barrier, sparking a manhunt which ended with his being nabbed five hours later.

The breaches prompted Deputy Prime Minister and Home Affairs Minister Teo Chee Hean to direct the Immigration and Checkpoints Authority of Singapore to "implement measures to better secure our checkpoints as soon as possible".

Similar intrusion detection systems were installed at three MRT train depots after vandals broke into the Changi depot in 2010 and Bishan depot in 2011.

The cost of installing steel fencing and intrusion detection systems at the three depots - the third one is the Ulu Pandan depot - was $6 million.