Chief Executive Carrie Lam on Wednesday reeled off a list of recent developments in Hong Kong that she said could threaten national security, including illegal protests, hate speech, and "extremist acts close to terrorism".

Her comments were made in a video clip released to mark "National Security Education Day" and came as liaison office director Luo Huining called for Article 23 national security laws to be enacted "as soon as possible".

Lam said the months of anti-government protests had challenged the rule of law and endangered public safety.

“Extremist actions that are close to terrorism emerged, including home-made bombs, possession of firearms and attacks on police officers," she said.

She condemned people she said had been spreading “cold-blooded and hate speech” on social media.

“It’s possible that the national security would be threatened if these illegal acts are not effectively curbed,” she warned.

Lam said the SAR government’s determination to ensure Hong Kong’s safety and stability shows it is not only responsible to the city, but also to the central government.