SINGAPORE - A car crash, masked gunmen and a police shoot-out disturbed the peace at the National Library on Tuesday (Sept 25) in the latest simulated terror attack exercise.

Home Team agencies and the community tested their joint response to a scenario in which a car crashed into a bollard in the atrium of the building in Victoria Street, before three masked gunmen emerged and sprayed bullets into a crowd.

Two of them were subsequently shot by responding police officers, while the remaining attacker made his way to the children's section in the library's basement.

Primary school pupils reading there were sent scurrying, trying to hide from the attacker.

The police soon arrived at the location and after a brief exchange of gunfire, took down the gunman, while Singapore Civil Defence Force (SCDF) officers treated the wounded.

The organised chaos was part of Exercise Heartbeat, a series of drills that have taken place each year since 2009.

Ms Sun Xueling, Senior Parliamentary Secretary for Home Affairs and National Development, observed Tuesday's exercise, which was organised by the Singapore Police Force (SPF) and SCDF, and supported by the National Library Board (NLB).

In the run-up to the exercise, about 500 staff and tenants at the building were trained in the SGSecure "run, hide, tell" protocol and improvised first-aid skills.

The NLB also reviewed its response plans, based on guidelines from the SPF and the Ministry of Manpower.

The exercise involved 180 participants, including Stamford Primary School pupils, SPF and SCDF officers, and NLB staff.

It featured crash-rated bollards at the library's atrium, which were installed recently.

"We have seen how vehicles overseas have been used to ram into pedestrians, so the installation of these crash-rated bollards will be a suitable and effective deterrent, should such an emergency situation arise," said Ms Sun.