Protesters took to the strees of cities around the world on Sunday as tensions rose in Hong Kong in the run-up to China’s 70th National Day celebration. Hong Kong's business and shopping belt was thrown into chaos as riot police repeatedly fired blue liquid - used to identify protesters - from a water cannon truck and multiple volleys of tear gas. Police were responding to demonstrators hurling Molotov cocktails at officers and targeting the government office complex. Sunday’s unrest followed on from a major organised rally on Saturday to mark the fifth anniversary of the Umbrella protests. During the Umbrella Movement, protesters occupied key thoroughfares in the city for 79 days to demand free elections for the city’s leaders but failed to win any concession. Saturday began peacefully, with demonstrators of all ages meeting peacefully at a harbourside park. But as the day wore on, violence marred The protests were sparked in June by a now-shelved extradition bill and have since snowballed into an anti-China, pro-democracy movement. The uproar came as one of the faces of the protests, Joshua Wong, announced plans to contest local elections and warned that any attempt to disqualify him would only spur more support for the months-long protests. Protesters in Sydney, London and a host of other cities took to the streets in sympathy with the Hong Kongers’ cause. In one of the largest solidarity marches in the Australian city since Hong Kong's pro-democracy movement began in March, black-clad participants took to the streets chanting "Add oil", a protest slogan denoting encouragement. Some protesters held signs that read "Save Hong Kong" and "Stop tyranny", while others carried yellow umbrellas or handed out paper cranes in scenes that played out in major cities across the country Sunday. Pro-China supporters stayed away, avoiding a repeat of the tense scenes that flared last month when opposing rallies held on the same day led to confrontations between the two sides. Bill Lam, 25, who attended demonstrations in Hong Kong before moving to Sydney for study two months ago, said protesters had become "very desperate" and simply wanted authorities to respect "their basic human rights". "I came here but I want to support them from Australia," he told AFP. "I feel so sad every night because I watch the live video (from Hong Kong) on Facebook and some social media."