More than 400,000 reports have now been made to the national security hotline and this shows Hongkongers support the national security law, a senior police official said on Friday.

Deputy Police Commissioner Edwina Lau, who heads the national security department, said there are still risks to security, even if it appears that peace has returned to the city.

Speaking to the media before she retires from the force, Lau took aim at crime suspects who have left the SAR.

"Some suspects who've fled Hong Kong I'll call them traitors because they are against the country and Hong Kong, called on different foreign governments to sanction judges and prosecutors involved in recent [national security] cases that are being tried in courts. Their actual goal is to pervert the course of justice," she said.

Lau has herself been sanctioned by the west, but said this only made her appreciate how important her job is.

She added that her department acts in a more transparent manner than counterparts in some western countries, as it always announces when arrests have been made.

Lau called on her successor to have an unyielding spirit, saying the road to safeguarding national security is fraught with difficulties.