HONG KONG--China’s most senior official in Hong Kong said on Wednesday the city should work to introduce national security legislation “as soon as possible” as violent protests last year had undermined its rule of law, prosperity and stability.

Luo Huining, chief of the Liaison Office and the most senior mainland political official based in the Chinese-ruled city, made the remarks during a speech commemorating China’s National Security Education Day.

In some of his strongest comments since taking office in January, Luo said national security was an obvious shortcoming in the former British colony and criticized what he described as foreign forces interfering in Hong Kong’s affairs.

“If the anthill eroding the rule of law is not cleared, the dam of national security will be destroyed and the well-being of all Hong Kong residents will be damaged,” Luo said.

“There’s a need to put effort into maintaining the national security legal system and enforcement system as soon as possible.”

Previous attempts to draft a new national security law for Hong Kong, known as Article 23, were met with mass protests in 2003 and abandoned.

Hong Kong returned to Beijing in 1997 under a “one country, two systems” formula that guarantees it broad freedoms not seen in mainland China, and its high degree of autonomy is widely seen as key to its prosperity as an international financial hub.

The Hong Kong Bar Association on Tuesday called on Beijing to “exercise restraint” in its comments on affairs in Hong Kong, warning that its views could be perceived as interference.

Three of Hong Kong’s top judges told Reuters for a special report published on Tuesday that the independence of the city’s judicial system was under assault from the Communist Party leadership in Beijing. The judiciary, they said, was in a fight for its survival.

Anti-government protests escalated in June last year and evolved over the months into a broad pro-democracy campaign, with many activists also angry about what they see as Beijing’s tightening grip over the city.

China denies meddling and blames the West for fomenting unrest.

While the coronavirus outbreak and social distancing restrictions aimed at stemming it have seen a lull in protests in the past few months, the unrest posed the biggest political challenge to Chinese President Xi Jinping.

Hong Kong’s Secretary for Security John Lee, speaking at the same event as Luo, expressed concern over “homegrown terrorism” in the city, while police chief Chris Tang said violent protests would not be tolerated.