Chaotic scenes of protesters rampaging through Hong Kong's legislature, trashing furniture and daubing graffiti over walls have sent jitters through the business community, which worries about the impact on the city's status as a financial hub.

Plumes of smoke billowed among gleaming sky-scrapers early on Tuesday as police fired tear gas to disperse protesters in the heart of the city, home to the offices of some of the world's biggest companies, including global bank HSBC.

Escalating unrest over a controversial extradition bill, which would allow people to be sent to mainland China for trial, grabbed global headlines and clouded Hong Kong's outlook as a finance hub, one of the city's main pillars of growth.