Hong Kong: Confrontations between pro-democracy demonstrators and authorities escalated across the streets of central Hong Kong as riot police fired tear-gas into crowds of thousands in an attempt to disperse a series of surging protests that have beset the city for three days.

Canisters of tear-gas were fired repeatedly to push back the largely peaceful protesters, filling the air with thick plumes of smoke that burnt the eyes and singed the skin, and transformed the thriving financial hub into a heaving night battleground.

While the tear-gas momentarily scattered crowds, it seemed only to galvanise protesters, who returned in droves, drawing further participants who decided to join the protests in solidarity, angered by what they considered to be a heavy-handed response by authorities.

"Before dinner, I never would have imagined that I would join [the protests]," Candy Lam, a 32-year-old bank employee, said.