* Protesters fire bows and arrows at police, wounding one
* Violence at universities some of the worst in months of protests
* City on edge amid five months of demonstrations 

Hong Kong protesters shot bows and arrows and hurled petrol bombs from a barricaded university campus on Sunday, as police charged and charged again, firing tear gas and blue liquid from water cannon after fiery clashes overnight.
Several protesters fired arrows from rooftops at the Hong Kong Polytechnic University amid some of the most dramatic scenes in over five months of unrest in the Chinese-ruled city.
Police said a media liaison officer was hit in the leg by an arrow. He was taken to hospital for treatment. A metal ball bit another officer in the visor, but he was not wounded.
Protesters stripped down to their underwear, before being hosed down by colleagues with fresh water to wash off the dye, not knowing what it contained.
Police also fired tear gas to try to break up protesters on the artery of Nathan Road in the Kowloon district of Mong Kok, a frequent venue for unrest.
Huge fires had lit up the sky at the university in the heart of Kowloon district overnight as protesters hurled petrol bombs, some by catapult, and police fired volleys of tear gas to draw them on to the open podium of the red-brick campus.
The clashes spread into Sunday evening, with protesters greeting each water cannon charge with petrol bombs.
"Rioters continue to launch hard objects and petrol bombs with large catapults at police officers," police said in a statement. "The shooting range of such large catapults can reach up to 40 metres ... Police warn that the violent activities in the Hong Kong Polytechnic University have escalated to rioting."
In the university courtyard, civil engineer Joris, 23, said he would be prepared to go to jail in his fight against the government. Those shooting arrows were protecting themselves, he said.
"The police violence has been over the top," he told Reuters. "The protesters have been reacting to the police. We haven't fought back as much as we could. I would be prepared for jail. We are fighting for Hong Kong."
Reuters correspondents heard a high-pitched wailing coming from at least one police vehicle, suggesting a new weapon in their crowd dispersal arsenal.
Chinese soldiers in a base close to the university were seen monitoring developments with binoculars, some dressed in riot gear with canisters on their chests.
Chinese soldiers dressed in shorts and T-shirts, some carrying red plastic buckets or brooms, emerged from their barracks on Saturday in a rare public appearance to help residents clear debris blocking key roads.
Parts of the Hong Kong Polytechnic University campus looked more like a fortress with barricades and black-clad protesters manning the ramparts with improvised weapons-like bricks, crates of fire bombs, and bows and arrows at the ready.
"We are not afraid," said a year-three student Ah Long, who chose not to disclose his full name. "If we don't persist, we will fail. So why not (go) all in," he said.
The campus is the last of five universities to remain occupied, with activists using it as a base to continue to block the city's central Cross-Harbour Tunnel.
The presence of China's People's Liberation Army (PLA) soldiers on the streets, even to help clean up, could stoke further controversy over Hong Kong's autonomous status at a time many fear Beijing is tightening its grip on the city.
The Asian financial hub has been rocked by months of demonstrations, with many people angry at perceived Communist Party meddling in the former British colony, which was guaranteed its freedoms when it returned to Chinese rule in 1997.
Beijing denies interfering and has blamed the unrest on foreign influences.
Clashes between protesters and police have become increasingly violent, posing the gravest popular challenge to Chinese President Xi Jinping since he came to power in 2012.
Xi has said he is confident the Hong Kong government can resolve the crisis. Until Saturday, Chinese troops in the city had remained inside their base during the protests.
Chinese troops have appeared on Hong Kong's streets only once since 1997, to help clear up after a typhoon in 2018. 
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