An exhibition commemorating the fifth anniversary of the Beijing-imposed national security law has opened in Hong Kong, featuring video footage and images from three major social movements, with city officials urging residents to remain vigilant against threats.

At the opening ceremony of the government-organised event on Thursday, Secretary for Security Chris Tang Ping-keung noted that as of June 1, 326 people had been arrested under relevant national security laws, including the legislation required under Article 23 of the Basic Law, the city’s mini-constitution, which was enacted in March last year.

According to Tang, residents should stay vigilant against four major risks, which still exist despite the stability brought by the laws, including external forces that attempt to smear and sanction, exiled individuals who promoted “Hong Kong independence”, local terrorism and soft resistance.

During the same occasion, Secretary for Justice Paul Lam Ting-kwok called on Hongkongers not to forget the history, ignore the reality, or stay aloof when national security threats emerge.

“National security risks are often not easily visible to the naked eye, but the facts are clear: hostile countries and forces are attempting to continuously suppress our country’s development,” Lam said, pointing to “a certain country” which attempted to interfere in Hong Kong’s national security cases through illegal sanctions and levies.

The entrance to the three-month thematic exhibition at the Hong Kong Museum of History is decorated with a so-called “time tunnel” installation that showcases videos and pictures documenting destructive acts during the 2014 illegal Occupy Central movement, 2016 Mong Kok riot and 2019 anti-government protests.

Chinese slogan “not to forget, but yet to finish” was printed on the entrance wall before residents entered the second part of the exhibition, which featured the city’s approach to unplugging the national security loopholes by enacting the Beijing-imposed national security law.