Hong Kong leader Carrie Lam announced on Wednesday the formal withdrawal of an extradition bill that triggered months of unrest and has thrown the Chinese-controlled city into its worst crisis in decades, Reuters reported.

The protests in the former British colony began in June over the bill, which would have allowed extraditions to mainland China, but have since evolved into a push for greater democracy.

It was not immediately clear if the announcement would help end the unrest.

"Too little, too late," said leading activist figure Joshua Wong on his Facebook page.

'One country, two systems"

Hong Kong's benchmark Hang Seng Index jumped after the report, trading up about 3.3%. The property index also jumped 6 percent. The withdrawal of the draft legislation was one of the protesters' key demands. Lam has said before that the bill was "dead" but she did not withdraw it.

Hong Kong returned to China under a "one country, two systems" formula that allows it to keep freedoms not enjoyed on the mainland, like the freedom to protest and an independent legal system, hence the anger at the extradition bill and perceived creeping influence by Beijing.

Lam told business leaders last week that she had caused "unforgivable havoc" by introducing the bill and that if she had a choice she would apologise and resign, according to a leaked audio recording.

At the closed-door meeting, Lam told the group that she now has "very limited" room to resolve the crisis because the unrest has become a national security and sovereignty issue for China amid rising tensions with the United States.

China has denounced the protests and warned about the impact on Hong Kong's economy. China denies it is meddling in Hong Kong's affairs but warned again on Tuesday that it would not sit idly by if the unrest threatened Chinese security and sovereignty.

Pepper spray

Riot police fired beanbag guns and used pepper spray - both anti-riot weapons - on Tuesday to clear demonstrators from outside the Mong Kok police station and in Prince Edward metro station, with one man taken out on a stretcher with an oxygen mask over his face, television footage showed.

Videos showing the man being apprehended by the police in the station have been widely shared on social media with protest groups and activists saying it is evidence of the police brutality they say is widespread and needs to be investigated.

The police, who have repeatedly denied using excessive force, did not immediately respond to a request for comment. Hong Kong police are due to hold a news conference at 4 p.m.

Three men, aged between 21 and 42, were taken to Kwong Wa Hospital late on Tuesday, a hospital authority spokeswoman said.

Two, including the man stretchered out of Prince Edward station, were in a stable condition and one had been discharged, she said.