HONG KONG • The simmering tensions in recent months as China tightens control over Hong Kong has led Chief Executive Carrie Lam to send out her strongest warning.

In cautioning those seeking to split the city from China, she said: "Hong Kong will not tolerate any acts that advocate Hong Kong's independence and threatens the country's sovereignty, security and development interests.

"We will fearlessly take actions against such acts according to the law in order to safeguard the interests of the country and Hong Kong," the leader wrote in a full text version of the policy address.

In her speech, she said the government will listen to views on implementing a national security law under Article 23 of the city's Basic Law. The article stipulates that the city has to enact a national security law on its own, but the previous legislation failed in 2003, after mass protests. While the government will try to create a suitable environment to enact Article 23, she warned that "it does not suggest we will turn a blind eye to the acts of violating the Constitution and the Basic Law".

Even before her speech started, pro-democracy lawmakers were escorted from the legislative chamber after shouting "Protect press freedom" and waving placards.

The former British colony was handed back to China in 1997 under the One Country, Two Systems set-up, with the 50-year guarantee of a high degree of autonomy and freedoms, including freedom of the press, not enjoyed elsewhere in China. Mrs Lam's comments were made in the wake of growing fears that its freedoms are under attack.

This, after Financial Times editor Victor Mallet was denied a work visa after he chaired a talk by pro-independence activist Andy Chan at the Foreign Correspondents' Club.

Mr Chan is a co-convenor of the Hong Kong National Party that was banned last month by the government, which said it posed a threat to national security having previously declared its goal to make Hong Kong a republic.