Hong Kong police have fired volleys of tear gas to disperse anti-government protesters, but demonstrators swiftly gathered elsewhere during another tense and restive weekend.
Weeks of increasingly violent protests have plunged Hong Kong into its most serious political crisis for decades, posing a serious challenge to the central government in Beijing.
On Saturday activists rallied across the city - with thousands thronging the airport arrivals hall for a second day - while elsewhere police displayed a new willingness to quickly and forcibly clear them from the streets.
Tear gas was used with little warning not long after several hundred activists who had marched through Tai Po in the north of the territory had barricaded an intersection in the Tai Wai neighbourhood.
They dispersed, as noxious smoke also filled the underground station there, bringing train passengers to tears.
"If the government thinks we'll give up and not come out anymore they're wrong," said student Chris Wong, 20, at Tai Po.
"Carrie Lam is now spreading lies and blaming us for destroying Hong Kong's economy. But she's the one who is destroying Hong Kong," he said.
"We'll continue to fight...but we're also going to be smart and wear them down."
China, meanwhile, demanded that the city's flag carrier Cathay Pacific Airways suspend staff involved in the demonstrations. One of its pilots was arrested last week.
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Lam's warning about the economy and China's targeting of a key Hong Kong business mark a toughening stance by authorities as they grapple with the crisis. It did not deter thousands of demonstrators.
Young people have been at the forefront of the protests, worried about the erosion of freedoms in Hong Kong by China but also concerned with issues such as wealth disparities in the city. However, older people have also been appearing.
Earlier on Saturday, in two separate protests, small groups of elderly Hong Kongers and families marched near the financial centre's business district. Both marches were peaceful.
Thousands of activists also filled the airport's arrivals hall for a second day, some sitting and shouting slogans, while others drew protest posters and greeted arriving passengers.
There were no reports of flight disruptions.
The protests began after Hong Kong's government tried introducing an extradition Bill that would have allowed defendants to be sent to mainland China for trial. The Bill has been suspended, but protesters have stepped up their demands and are now calling for greater democracy and Lam's resignation.
More protests are planned for Sunday, including one in Sham Shui Po, a working-class neighbourhood that has been the scene of violent confrontations between activists and police.
The government announced that public buildings there such as pools and libraries would be shut on Sunday afternoon.