The latest round of clashes began when protesters broke away from the authorized anti-government rally in Hong Kong's Victoria Park.
In the meantime, the protesters demands evolved to include calls for greater democracy, an independent investigation into alleged police brutality and the resignation of the city's leader, Carrie Lam.
In North Point, tensions were running high as protesters gathered in a district known for its triad-linked loyalty to the ruling Chinese Communist Party, after a man in a red shirt ran out of a restaurant and attacked a young man wearing black: the usual colour worn by supporters of the anti-extradition movement.
"All the money from the mainland that has propped up Hong Kong property markets could reverse as quickly as it flowed in", he said. The protests, however, were not abating, and more are planned for this weekend, including at the airport, where protesters holding signs staged a sit-in at the arrival and departure halls Friday.
In the working class district of Sham Shui Po, over a thousand people, including middle aged and elderly marched to protest against the government.
"The most pressing and overriding task at present is to stop violence, end the chaos and restore order, so as to safeguard our homeland and prevent Hong Kong from sinking into an abyss", Zhang said.
"And if Hong Kong is at odds with China, it's a problem for everyone, including us".
The photograph is likely to add fuel to China's narrative that the U.S.is behind the Hong Kong protests, which began in June as a reaction to a proposed law allowing people accused of certain crimes in Hong Kong - which maintains its own legal system - to be sent to face justice in mainland China.
Fong, who was carrying 10 recently purchased laser pointers, none of which was equipped with a power supply, was later released without charge.
Hong Kong International Airport is one of the busiest airports in the world and handles as many as 1,100 passengers and cargo flights every day, with services between the city and about 200 international destinations, reported CNN.
Commerce Secretary Edward Yau Tang-wah said 22 countries and regions, including the USA, have issued travel warnings for Hong Kong.
Local media outlets reported that suspected undercover police officers had dressed-up as protesters to make surprise arrests on Sunday night.
After the news of the U.S. and Hong Kong public relations meeting yesterday, the Chinese Foreign Ministry's Hong Kong Office immediately issued a notice criticizing the USA and directly them not to contact Huang Zhifeng and Luo Guancong, two heads of the "Hong Kong independence organizations".
"I'm taking issue with the Chinese saying they issued a formal protest when in fact they harassed an American diplomat", Ortagus said at the press conference.
Police said on Sunday they had arrested 16 people during the protests on Saturday for charges including unlawful assembly and possession of an offensive weapon.
"The situation is of particular concern for Canada in light of the 300,000 Canadians living in Hong Kong", said Global Affairs spokesperson Guillaume Berube in a statement.