Hong Kong police fired volley after volley of tear gas to break up thousands of anti-government protesters, most dressed in black and wearing face masks, in Victoria Park, a traditional venue for rallies and vigils, and surrounding streets. It was an early, feverish response to nip in the bud a rally billed as an "emergency call" for autonomy for the former British colony that was promised its freedoms when it returned to Chinese rule in 1997. The fast-moving crowds headed to the park through the Causeway Bay shopping district, some pulling up metal fencing and using a football goal to build barricades, their actions masked by others holding umbrellas. Activists threw at least one petrol bomb. Many sang the British and U.S. national anthems, waving multi-national flags and a few calling for independence, a red line for Communist Party leaders in Beijing who have vowed to "crush the bones" of anyone pursuing such a move. Police using loud-hailers warned them to disperse, saying they would be prosecuted for holding an illegal assembly on the 22nd straight weekend of protest. The protesters took off in all directions, many throwing bricks as they charged towards Central, building makeshift barricades on the way. Their route was taking them through the Wan Chai bar district where many rugby fans were gathered in bars pouring out on to the streets for the World Cup final in Japan. Police fired more tear gas near police headquarters on Hennessy Road, the main artery to Central. Protesters have taken to the streets for five months of sometimes violent unrest, angry at perceived Chinese meddling with Hong Kong's freedoms, including its legal system. China denies the charge. Activists have attacked police with petrol bombs, set street fires and trashed government buildings and businesses seen as pro-Beijing. One policeman was slashed in the neck with a knife last month. Police have responded with tear gas, pepper spray, water cannon, rubber bullets and occasional live rounds. Several people have been wounded. Saturday's rally was not given official police permission, as is required, but that has not stopped people gathering in the past. Face masks were banned under a resuscitated colonial-era emergency law. "It does not make sense (for this assembly to be unauthorized)," said one protester, 55, who only gave her name as Lulu. "This is our human right... The global support is very important. We are not only in Hong Kong. The whole world supports Hong Kong." Simon Tse, 84, came with his two daughters. "I haven't joined a protest on the street since the Oct. 1 march which became quite violent," he told Reuters. "But today I am joining because we are calling for international support, urging help from 15 countries. This is the last chance for Hong Kong people." Government data on Thursday confirmed that Hong Kong slid into recession in the third quarter for the first time since the global financial crisis of 2008. Hong Kong is a semi-autonomous "special administrative region" of China according to the "one country, two systems" formula under which it returned to Chinese rule. -Reuters