As in previous demonstrations, violence broke out at the end of the day. By early evening, protesters had vandalized a subway station in central Hong Kong that police had closed and set a fire around one of its entrances. Demonstrators wearing face masks and helmets smashed station windows, leaving glass piled on the sidewalk. They tossed street signs, emptied trash cans down the subway stairwells and began building barricades.

Later Sunday, police fired tear gas to disperse protesters in the popular shopping district of Causeway Bay.

It was the second consecutive night of clashes, despite the decision of Hong Kong leader Carrie Lam to withdraw the widely unpopular extradition bill that sparked the months-long political crisis — a clear sign that her concession has been rejected by pro-democracy protesters.

A protester waves an American flag in Hong Kong on Sunday. (Vincent Yu/AP)

As dissent in Hong Kong and the accompanying police crackdown continue, Lam and her government face the possibility of growing international criticism, particularly from the United States, where lawmakers have returned from their summer recess.

Authorities have targeted prominent activists who have not been at the forefront of the recent protests. Former student leader Joshua Wong, who is due to visit the United States soon to testify at a congressional hearing, was arrested at the city’s airport while returning from Taiwan, he said through a legal representative Sunday evening.

Wong was detained for “breaching bail conditions” following his arrest last month but said this was due to mistakes on his bail certificate. He called his detention “utterly unreasonable” and said he expected to be released Monday.

Organizers handed a petition to a consulate official calling for swift congressional passage of the bipartisan Hong Kong Human Rights and Democracy Act. The protest was expected to draw the ire of Beijing, which has accused the United States of meddling in the months-long political crisis and warned that Hong Kong is an internal Chinese matter.

Members of the Congressional Executive Commission on China reintroduced the bill in June, days after a million people marched to call for the extradition legislation to be scrapped.

In a statement late Sunday, the Hong Kong government said it has “regret” about the reintroduction of the act and “reiterates that foreign legislatures should not interfere in any form in the internal affairs” of Hong Kong.

The congressional bill would require an annual review of the special treatment afforded by Washington to Hong Kong under the United States-Hong Kong Policy Act of 1992, including the trade and business privileges Hong Kong enjoys separate from China. It would also direct the administration to freeze the assets and deny U.S. entry to people found to be “suppressing basic freedoms” in Hong Kong.

“The Chinese government is breaking their promises to give freedom and human rights to Hong Kong,” said a 24-year-old protester in a red “Make America Great Again” hat.

“We want to use the U.S. to push China to do what they promised over 20 years ago,” said the man, who spoke on the condition of anonymity. “The U.S. government can make China think: Do they really want to lose Hong Kong?”

Protesters march from the U.S. Consulate in Hong Kong on Sunday. (Carl Court/Getty Images)

Lam, Hong Kong’s chief executive, suspended the extradition bill in mid-June but didn’t fully withdraw it until Wednesday. In the weeks between those actions, the protests expanded in intensity and scope to encompass Beijing’s erosion of the “one country, two systems” framework, under which Hong Kong has operated since Britain handed it back to China in 1997.

In an indication of the growing anti-China flavor of protests, demonstrators on Sunday carried posters and stickers depicting the Chinese flag with its yellow stars rearranged into swastikas.

Swastikas with the term “Chinazi” were spray-painted in the Central district.

Lam’s concessions, which also included beefing up an independent police oversight committee, drew hostility among protesters, who want her to meet the four other demands they have laid out.

Her move to withdraw the bill “was a public relations exercise vis-a-vis Beijing and Washington,” said Andreas Fulda, a senior fellow at the University of Nottingham’s Asia Research Institute and author of a book on efforts at democratization in China. He said Lam “has every reason to be worried about a strong U.S. response” when Congress sits again.

The growing distrust and public animosity toward police was evident again on Sunday. Dozens of officers stopped and searched protesters on a glitzy stretch of luxury shops in the Central district. Bystanders jeered, yelling “shame,” and cheered when a group of tactical officers left the area.

On Saturday, demonstrators planned a second “stress test” to disrupt transportation to Hong Kong International Airport, but it was thwarted by police. Last weekend, protesters caused massive traffic jams and rail delays to the airport. Police stymied Saturday’s effort by stationing officers in riot gear at subway stops and ferry terminals and boarding buses to check for demonstrators.

Demonstrators pushing for a stronger U.S. government response say Washington has several options, including tweaking language in the Hong Kong Policy Act to limit government-to-government interaction and alter the U.S. economic relationship with Hong Kong.

“We are in a very urgent situation,” said Cody, a 30-year-old IT worker. “We need all the support we can get.”

Members of Congress have been watching Hong Kong and discussing legislation through the summer recess. House Speaker Nancy Pelosi (D-Calif.) said last week that lawmakers should move quickly to advance the bill. Senate Majority Leader Mitch McConnell (R-Ky.) said he would support legislation to “enhance” the Hong Kong Policy Act he helped to pass in 1992.

A barricade burns at an entrance to a train station in Hong Kong. (Carl Court/Getty Images)

The push to pass the law has frustrated pro-Beijing lawmakers in Hong Kong. Felix Chung, one such lawmaker, traveled with colleagues to Montana last month to meet with congressmen and senators.

“Traditionally, these bills targeting specific countries, they are developing countries, with dictators in those countries,” he said. “But Hong Kong has been so close to the U.S., economically and socially, it has never been a target of the U.S. government, so why should they use such a particular bill to punish Hong Kong?”

While leaders from both parties have been vocal in their support of Hong Kong’s protesters, Trump has taken a largely hands-off approach. He said last month that Chinese President Xi Jinping could “quickly and humanely solve the Hong Kong problem.” Previously, he described the protests as “riots,” a term used by Hong Kong authorities and a characterization protesters are fighting to have withdrawn as one of their demands.

Kurt Tong, who served as U.S. consul general in Hong Kong until this summer, said the administration has treated Hong Kong as a “second-tier” issue. In a speech in Washington, he said the administration has put more focus on Iran, North Korea and the trade war with China.