Swastikas with the term "Chinazi" were also spray painted in the Central district.
Lam's concessions, which also included beefing up the independent police oversight committee, were met with hostility among protesters, who want her to meet the four other demands they have laid out.
Her move to fully withdraw the bill "was a public relations exercise vis-a-vis Beijing and Washington," said Andreas Fulda, the author of a book on efforts at democratization in China and a senior fellow at the University of Nottingham's Asia Research Institute. "Carrie Lam has every reason to be worried about a strong US response" when Congress sits again, he said.
The growing distrust and public animosity toward police was again evident on Sunday after dozens of police stopped and searched protesters on a glitzy stretch of road in the Central district lined with luxury shops. Bystanders jeered at the police, yelling "shame" and cheered when a group of tactical officers left the area.
"They think that this is perhaps a tactical retreat and a way to pacify the movement, but it is so evident that it doesn't address the elephant in the room, which is the militarization of the Hong Kong Police Force," he added.
Earlier Saturday, a second "stress test" was scheduled by demonstrators to disrupt transportation to Hong Kong International Airport but it was thwarted by police. Last weekend protesters caused massive traffic jams and rail delays on lines heading toward the airport. Police stymied Saturday's effort with officers in riot gear stationed at subway stops and ferry terminals as well as boarding buses to check for demonstrators.
"We are in a very urgent situation. We need all the support we can get," said Cody, a 30-year-old IT worker attending the march.
Those who are pushing for a stronger US government response on the situation in Hong Kong say Washington has several options, including tweaking language in the Hong Kong Policy Act in a way that would effectively limit government to government interaction and alter the US economic relationship with Hong Kong.
Conversations have been ongoing between lawmakers and members of foreign relations committees over the summer, as Congress has been in recess, and lawmakers have been watching further developments before deciding on how actively to push the bill when back in session.
US House Speaker Nancy Pelosi, D-Calif, said earlier this week that lawmakers should move to quickly advance the bill. Senate Majority Leader Mitch McConnell, R-Ky, said in an interview Tuesday that he would support legislation to "enhance" the Hong Kong Policy Act he helped to pass in 1992.
The push to pass the law has frustrated pro-establishment lawmakers in Hong Kong.
"Traditionally, these bills targeting specific countries, they are developing countries, with dictators in those countries," said Felix Chung, a pro-Beijing lawmaker who traveled as part of a delegation of Hong Kong lawmakers last month to Montana to meet with congressmen and senators.
"But Hong Kong has been so close to the US, economically and socially, it has never been a target of the US government, so why should they use such a particular bill to punish Hong Kong?" he added.
While leaders from both parties have been vocal in their support of Hong Kong's protesters, Trump has taken a largely hands-off response to the upheaval. Last month, he said Chinese President Xi Jinping could "quickly and humanely solve the Hong Kong problem." Previously, he described protesters 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 US Consul General in Hong Kong until this summer, said during a speech in Washington in late July that Hong Kong was treated as a "second-tier" issue by the administration, which put more focus on Iran, North Korea and the trade war with China.