Police commissioner Joe Chow on Saturday called for continued vigilance against national security threats even in times of peace, saying a recent case demonstrate such risks remain.

Four men believed to be members of a Taiwan-based organisation that promotes Hong Kong independence were arrested on Wednesday. Three of them have been jointly charged with one count of conspiracy to commit secession.

"This case shows that national security risks always exist. We shouldn't let our guard down just because things appeared to be relatively calm and peaceful," Chow said.

"The police force has a primary responsibility to safeguard national security. But at the same time, safeguarding national security is every resident's responsibility."

Chow, who spoke to reporters following a passing-out parade of officers, noted that there were more than 1,220 new recruits in the past financial year, up some 25 percent compared to the 2023-24 period.

The police chief also said new arrangements were put in place on July 1 to fast-track the recruitment of officers, with the entire process expected to be cut down to around four months.

Under the new policy, those who have scored at least level 4 in both Chinese and English in the Diploma of Secondary Education Examination, and passed the aptitude test of the government's examination for recruiting civil servants, will be considered to have passed the probationary inspector written test.