A protester uses a sharp object against a police officer. The Hong Kong Police Force's newly formed special unit to safeguard national security begins functioning decisively to end riots in the city on Wednesday. More than 370 people have been arrested as of press time. Photo: AFP

There's a call for more secessionists in Hong Kong, including Joshua Wong Chi-fung, Jimmy Lai Chee-ying and Tai Yiu-ting, to be investigated after four people who claimed to be students were arrested for suspected secessionist activities in the first major operation of the Hong Kong police's new national security unit on Wednesday. 

A Hong Kong Police Force spokesperson told the Global Times on Thursday that this is the first arrest conducted by the new national security department under the police force against the city's secessionist groups since the department was officially established in early July.

The day after the national security law for Hong Kong took effect on June 30, about 370 protesters were arrested for breaching the new law, and 10 of them were apprehended. Many secessionists and their groups shut or rebrand their social media accounts to avoid violating the new security law.

The spokesperson said that acting on intelligence and after a thorough investigation, the national security department arrested three men and a woman between the ages of 16 and 21 in Yuen Long, Tuen Mun and Sha Tin on Wednesday. They were suspected of publishing content about secession, and inciting or abetting others to push for secession on online social media platforms in July, which violate Article 20 and Article 21 of the national security law for Hong Kong.

Police seized mobile phones, computers and documents, the spokesperson said. He stressed that the internet is not beyond the law. Under Hong Kong law, most of the ordinances stipulated in the real world may also apply in the cyber world. 

Senior Superintendent Li Kwai-wah, of the national security department under the HKPF, announced at a press conference on Wednesday night that they found a group setting up an organization on a social platform advocating for "Hong Kong independence." The platform of the organization claimed to establish a "Hong Kong Republic." There was also a manifesto inciting others to join the group. 

They could be sentenced upto 10 years in prison, and police can take DNA samples from those arrested, Li said.

The police force did not disclose the names of the suspects and the organization, but Studentlocalism, a secessionist group, announced on Facebook on Wednesday night that Tony Chung Hon-lam, one of the former conveners of the organization, was "arrested for inciting secession." 

On June 30, Studentslocalism announced it had shut down its headquarters in Hong Kong, the same day the national security law for Hong Kong took effect, and said all the group's affairs would be handled by overseas members instead. 

But the group continued advocating "Hong Kong independence" on an overseas social media platform after June 30. In a post on Twitter on July 2, they said, "disintegrate China."

Hong Kong law states that the suspects could be detained for no more than 48 hours. "During that period, police need to prepare evidence and submit them to the Department of Justice for prosecution. According to the national security law for Hong Kong, they will be denied bail unless the judge has reason to believe that they will not endanger national security," Kennedy Wong Ying-ho, solicitor of the Supreme Court of Hong Kong, told the Global Times on Thursday. 

These students may think they can escape from the law because they published their secessionist opinions on overseas social media platforms. However, as long as they were in Hong Kong, they are still under watch, Wong said. But Wong stressed that the law should severely punish the organization and leaders who incite subversion, but offer leniency to underage suspects deceived by wrong values.  

The Hong Kong Special Administrative Region (HKSAR) government has enough space for them to express their views. No country will allow a subversive movement, and it should not be different if it happens in China, Nixie Lam, a Tsuen Wan district councilor, told the Global Times on Thursday, calling for a more thorough investigation into secessionists such as Joshua Wong, who continues to incite hatred and defame police actions on social media. 

Other people like Jimmy Lai, who continues to smear the new security law, and illegal "Occupy Central" movement leader Benny Tai, who openly urged opposition candidates in the "primaries" to paralyze the HKSAR government if they got elected, should be seriously investigated as soon as possible, Kennedy Wong said.