Secretary for Security Chris Tang said that while the number of people violating national security laws have been falling in recent years, society as a whole should always remain vigilant.

He made the comment in an interview published on Friday marking three years into the current term of government.

Tang stressed that officials will keep working to improve the laws, such as the recent additions of national security clauses governing eateries licence holders and trade unions.

He said his bureau will soon publicise guidelines for civil servants – as required by law – to explain how all government workers need to safeguard security.

For example, if cleaners encounter a potential national security risk, Tang said they should report it.

"When a cleaner sees some slogans at work that could endanger national security, then there's a need to report the potential violation," he said.

And citing the example of what civil servants who vet funding applications should do, he said: "When you find out that the background of a group is suspicious or it might be involved in something that endangers national security, then there's no reason to approve the funding."

Tang said security officials will assess risks as part of efforts to ensure that the National Games and the Legislative Council elections this year will be held smoothly.

Such work, he stressed, include patrolling the internet and monitoring to see if anyone might be using online tools to wreak havoc.

In the past year, Tang said, 13 people had been identified as absconders under the Safeguarding National Security Ordinance. As such, people have been banned from providing financial assistance or handling funds related to them.

He said such work is effective as it sends a clear message that those who violate the security law could face a very steep price.