HONG KONG >> Thousands of protesters blocked entry to Hong Kong’s government headquarters Wednesday, delaying a legislative session on a proposed extradition bill that has heightened fears over greater Chinese control and erosion of civil liberties in the semiautonomous territory.

The overwhelmingly young crowd overflowed onto a major downtown road as they overturned barriers and tussled with police outside the building that also houses the chambers where the legislature was to discuss the bill, which would allow criminal suspects in Hong Kong to be sent for trial in mainland China.

A curt government statement said the session scheduled to begin at 11 a.m. would be “changed to a later time.” An earlier statement said staff members were advised not to go to work and those already on the premises were told to “stay at their working place until further notice.”

The delay appeared to be at least a temporary victory for the bill’s opponents, whose protests have prompted Hong Kong’s biggest political crisis since pro-democracy demonstrations closed down parts of downtown for more than three months in 2014. Some businesses closed for the day, and labor strikes and class boycotts were called.

The protests are a challenge to China’s ruling Communist Party and President Xi Jinping, who has in the past said he would not tolerate Hong Kong being used as a base to challenge the party’s authority. But they are also giving vent to young Hong Kongers alienated by a political process dominated by the territory’s economic elite.

Protesters said they hoped the blockade would persuade Chief Executive Carrie Lam’s administration to shelve the proposed amendments to the Fugitive Offenders Ordinance and the Mutual Legal Assistance in Criminal Matters Ordinance.

“We want the government to just set the legislation aside and not bring it back,” said a protester who gave only his first name, Marco, to avoid possible repercussions from authorities.

The protest was a watershed moment for Hong Kong’s young generation, who face difficult job prospects and skyrocketing housing prices, said another protester, who gave her name as King, also out of fear of repercussions.

“We have to stand up for our rights or they will be taken away,” she said.

Dressed in black T-shirts and jeans, many protesters appeared undaunted by demands to disperse from police who briefly used pepper spray and detained dozens overnight Tuesday. They also appeared mindful of Beijing’s growing use of electronic surveillance such as facial recognition technology to build dossiers on those it considers politically unreliable, with many donning surgical or anti-pollution masks to hide their features, as well as to safeguard against tear gas.

Such protests are never tolerated in mainland China, and Hong Kong residents can face travel bans and other repercussions if they cross the border.

Under its “one country, two systems” framework, Hong Kong was supposed to be guaranteed the right to retain its own social, legal and political systems for 50 years following its handover from British rule in 1997. However, China’s ruling Communist Party has been seen as increasingly reneging on that agreement by forcing through unpopular legal changes.

The government pushed ahead with plans to present the amendments to the legislature on Wednesday despite a weekend protest by hundreds of thousands of people that was the territory’s largest political demonstration in more than a decade.

A crowd began gathering outside the Legislative Council on Tuesday night, and the U.S. Consulate warned people to avoid the area, exercise caution and keep a low profile.

The legislation has become a lightning rod for concerns about Beijing’s increasing control over the semi-autonomous territory.

Lam has consistently defended the legislation as necessary to close legal loopholes with other countries and territories. A vote is scheduled on June 20.

Sunday’s protest was widely seen as reflecting growing apprehension about relations with the Communist Party-ruled mainland, where Xi has said he has zero tolerance for those demanding greater self-rule for Hong Kong.

Critics believe the extradition legislation would put Hong Kong residents at risk of being entrapped in China’s judicial system, in which opponents of Communist Party rule have been charged with economic crimes or ill-defined national security offenses, and would not be guaranteed free trials.

Lam, who canceled her regular question and answer session on Wednesday, said the government has considered concerns from the private sector and altered the bill to improve human rights safeguards. She said without the changes, Hong Kong would risk becoming a haven for fugitives.

She emphasized that extradition cases would be decided by Hong Kong courts.

Opponents of the proposed extradition amendments say the changes would significantly compromise Hong Kong’s legal independence, long viewed as one of the crucial differences between the territory and mainland China.

Hong Kong currently limits extraditions to jurisdictions with which it has existing agreements and to others on an individual basis. China has been excluded from those agreements because of concerns over its judicial independence and human rights record.

Those in Hong Kong who anger China’s central government have come under greater pressure since Xi came to power in 2012.

The detention of several Hong Kong booksellers in late 2015 intensified worries about the erosion of Hong Kong’s rule of law. The booksellers vanished before resurfacing in police custody in mainland China. Among them, Swedish citizen Gui Minhai is being investigated on charges of leaking state secrets after he sold gossipy books about Chinese leaders.

In May, Germany confirmed it had granted asylum to two people from Hong Kong who, according to media reports, were activists fleeing tightening restrictions at home. It was the first known case in recent years of a Western government accepting political refugees from Hong Kong.