Hundreds of Hong Kong pro-democracy activists blocked some routes to the city's airport Sunday as the financial hub began cleaning up after another night of violent protests marked by fires, tear gas and police beatings.

Operators of the Airport Express train said it had suspended services on Sunday afternoon, while black-clad protesters hiding from CCTV cameras under umbrellas -- built barricades at the airport bus station and attempted to stop traffic on the main road leading to terminals.

Flights had so far not been disrupted, and riot police were deployed inside the terminals.

The airport is covered by an injunction banning protesters from entering -- imposed after a shutdown in August which ended in ugly clashes.

But protesters have routinely ignored legal moves to bans their rallies and actions -- since the anti-government movement sprang to life three months ago.

The protests were sparked by an attempt by Hong Kong's Beijing-backed government to pass a now-shelved extradition bill, but have expanded into a wider pro-democracy push.

On Sunday, city sanitation workers were seen clearing debris and removing graffiti after a night of pitched battles between protesters and police.

Hours before a huge fire burned for over an hour in the city's commercial district as chaos rippled through the centre of a city usually renowned for its stability and prosperity.

"I’m really, really tired. I think many Hong Kong people had a sleepless night yesterday," said 18-year-old student protester called May.

"I almost couldn’t manage to get up, but I’m determined to go today."

Hardcore demonstrators Saturday hurled petrol bombs at government buildings and police, who responded with tear gas and water cannon laced with chemical dye before making mass arrests inside the city's underground metro stations.