A woman walks by the Government of Hong Kong Special Administrative Region office building in Beijing, on Tuesday. AP

China's parliament passed national security legislation for Hong Kong on Tuesday, setting the stage for the most radical changes to the former British colony's way of life since it returned to Chinese rule 23 years ago.

READ MORE

China says will restrict visas for some Americans over Hong Kong row

Riot police deployed across Hong Kong as US, China tensions flare up again

State media is expected to publish details of the law — which comes in response to last year's often-violent pro-democracy protests in the city and aims to tackle subversion, terrorism, separatism and collusion with foreign forces — later on Tuesday.

Amid fears the legislation will crush the global financial hub's rights and freedoms, and reports that the heaviest penalty under it would be life imprisonment, prominent pro-democracy activist Joshua Wong said he would quit his Demosisto group.

Pro-China supporters display flags during a rally near the government headquarters in Hong Kong on Tuesday. AFP

"It marks the end of Hong Kong that the world knew before," Wong said on Twitter.

The legislation pushes Beijing further along a collision course with the United States, Britain and other Western governments, which have said it erodes the high degree of autonomy the city was granted at its July 1, 1997, handover.

The United States began eliminating Hong Kong's special status under U.S. law on Monday, halting defence exports and restricting the territory's access to high-technology products.

Hong Kong leader Carrie Lam, speaking at her regular weekly news conference, said it was not appropriate for her to comment on the legislation as the meeting in Beijing was still going on, but she threw a jibe at the United States.

A pro-China supporter holds a Chinese and Hong Kong national flag in Hong Kong, on Tuesday. Kin Cheung/AP

"No sort of sanctioning action will ever scare us," Lam said.

Lau Siu-kai, vice-president of a think-tank under the Beijing cabinet's Hong Kong and Macau Affairs Office, told Reuters the law was passed unanimously with 162 votes. It is expected to come into force imminently.

The editor-in-chief of the Global Times, a tabloid published by the People's Daily, the official newspaper of China's ruling Communist Party, said on Twitter the heaviest penalty under the law was life imprisonment, without providing details.

Authorities in Beijing and Hong Kong have repeatedly said the legislation is aimed at a few "troublemakers" and will not affect rights and freedoms, nor investor interests.

Reuters