A record 2.2 million people voted in the city-wide legislative election as fears grow Beijing is tightening its grip on the semi-autonomous city.
It was the highest turnout since Hong Kong was returned to China by Britain in 1997 and comes as tensions have reached unprecedented highs over Beijing interference.
Hong Kong's freedoms were protected for 50 years in the handover agreement, but many believe they are disappearing.
Young activists particularly have lost faith in the "one country, two systems" deal under which the city is governed, which grants it much greater liberties than on the mainland.
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As results rolled in, four of the new breed of candidates were confirmed to have won seats, with a fifth also on course for victory.
Among them was Nathan Law, 23, leader of the 2014 "Umbrella Movement" rallies, who came second in his constituency.
Hong Kong is split into five geographical constituencies, each with several seats in the Legislative Council (LegCo), Hong Kong's lawmaking body.
Law and his new party Demosisto are calling for a referendum on independence, emphasising Hong Kongers' right to choose whether they want to split from China.
"Young people have a sense of urgency when it comes to the future."
With the pro-democracy camp divided between those who back the idea of possible independence and those who are more wary of the once taboo notion, Law said he would seek unity.
"We have to be united to fight against the (Chinese) Communist Party," he told AFP.
Law has previously distanced himself from the more radical "localist" movement, which includes activists who are stridently pro-independence and have previously advocated violence.
Young campaigners have been galvanised by a number of incidents which have pointed to increased Beijing interference.