- The initial protests were lit by a now-suspended bill that would have allowed extraditions to mainland China.
- Beijing's authority faces its most serious challenge since Hong Kong was handed back to China in 1997.
- Sunday's rally will be the seventh weekend in a row that protesters have come out en masse.
- It will follow a now well-trodden route through the main island's streets.
Hong Kong is bracing for another huge anti-government march on Sunday afternoon with seemingly no end in sight to the turmoil engulfing the finance hub, sparked by years of rising anger over Beijing's rule.
The city has been plunged into its worst crisis in recent history by weeks of marches and sporadic violent confrontations between police and pockets of hard-core protesters.
The initial protests were lit by a now-suspended bill that would have allowed extraditions to mainland China.
But they have since evolved into a wider movement calling for democratic reforms, universal suffrage and a halt to sliding freedoms in the semi-autonomous territory.
In a city unaccustomed to such upheaval, police have fired tear gas and rubber bullets while the parliament has been trashed by protesters – as Beijing's authority faces its most serious challenge since Hong Kong was handed back to China in 1997.
Sunday's rally – which will follow a now well-trodden route through the main island's streets – will be the seventh weekend in a row that protesters have come out en masse.
Generally, the marches have passed off peacefully but are followed by violence between riot police and small groups of more hard-core protesters.
Security was tightened in the city centre, with metal street fencing often used by protesters to build barricades removed ahead of the march, and large water-filled barriers thrown up around the police headquarters.
The huge crowds have had little luck persuading the city's unelected leaders – or Beijing – to change tack on the hub's future.
Under the 1997 handover deal with Britain, China promised to allow Hong Kong to keep key liberties such as its independent judiciary and freedom of speech.
But many say those provisions are already being curtailed, citing the disappearance into mainland custody of dissident booksellers, the disqualification of prominent politicians and the jailing of pro-democracy protest leaders.
Authorities have also resisted calls for the city's leader to be directly elected by the people.