SINGAPORE - Closing Hougang MRT station on Sunday (April 2) following the discovery of an unattended bag there was "the right thing to do", said Minister for Law and Home Affairs K. Shanmugam on Tuesday.

Recounting the events leading to the station's closure to delegates and exhibitors at the homeland security exhibition Milipol Asia-Pacific 2017, Mr Shanmugam said that the camera at the station had picked up someone leaving a bag behind and walking off.

"The immediate response was to close the station down," he said. "There will be some questions whether we overreacted, but if we had not, people would have said 'why'?"

He affirmed that "closing it was the right thing to do".

Citing a report by The Straits Times on the closure, Mr Shanmugam went on to underscore the importance of SGSecure - a national movement that seeks to sensitise, train and mobilise Singaporeans to play a part in dealing with and preventing terrorism - as well as the movement's mobile app.

In the report, an SGSecure user told The Straits Times he received an alert on the app urging the public to stay away from Hougang MRT. The user only went to the station after the app said it was safe to do so.

"So it's working," said Mr Shanmugam. "There is a general sensitisation to this idea."

He also said that it was the Government's duty to send the SGSecure message across, and that the Government intends "to go to every single household in Singapore (to do so)".

"We have done (this for) about 60,000 households since we started," he added, before saying that every household in Singapore would be reached over the next three years.

The SGSecure movement was launched by Prime Minister Lee Hsien Loong in September last year.

A 39-year-old man, who left the luggage unattended at the platform, was arrested for causing public nuisance. The Straits Times understands that he is currently out on bail, pending police investigations.