His release comes a day after organisers of the protest calling for Lam to quit over a controversial extradition bill said almost two million black-clad people joined Sunday's march to government offices.
Hong Kong activist Joshua Wong called on the city's pro-China leader Carrie Lam to resign after he was released from prison Monday, a day after one of the largest street protests in Hong Kong’s history forced an apology from the city’s top official over a divisive extradition bill.
"She is no longer qualified to be Hong Kong's leader. She must take the blame and resign, be held accountable and step down," Wong told reporters.
Joshua Wong Chi-fung is a Hong Kong pro-democracy activist. He was one of the leaders of the 2014 Occupy Movement. In August 2017, he was jailed for six months for storming the government headquarters compound at Tamar, Admiralty, which sparked the 79-day protest.
Hong Kong protesters: Chief Executive Lam must go
Wong was released from prison one month early, as the government reels from one of the largest mass protests since the former British colony’s return two decades ago.
"I will join to fight against this evil law," said Wong, 22, who was one of the leaders of the 2014 "Umbrella" pro-democracy protests that blocked major roads in the Chinese-ruled city for 79 days.
"I believe this is the time for her, Carrie Lam the liar, to step down."
Before he was jailed, both Wong and his supporters had called for the Hong Kong government to scrap the extradition proposal.
Wong was just 17 when he stood at the forefront of the broad civil disobedience movement that presented China's Communist Party rulers in Beijing with one of their biggest political challenges in decades.
The protests against the extradition bill have become the most significant challenge to China's relationship with the territory since it was handed back by Britain 22 years ago.
While Lam delayed the bill at the weekend, it has yet to be completely shelved, despite widespread concern that the status of Hong Kong as a financial hub could be eroded by changes to the rule of law.