A protester has been shot in the chest as police fired live rounds during clashes in Hong Kong, according to activists and local media.

The Demosisto protest group shared a video on social media that appeared to show a police officer firing a handgun into the chest of an approaching protester at near-point-blank range.

The video, captured and posted online by a Hong Kong University student union group, showed the police officer was surrounded by protesters throwing objects when he opened fire.

A police official confirmed an officer had opened fire in the Tsuen Wan area, and that a protester had been hit. The man's friend told reporters he was in a critical condition at Princess Margaret hospital in Kwai Chung.

It is the first time a protester has been struck by police live fire since the political unrest began in June, though officers have fired warning shots into the air on several occasions in the past.

Hong Kong protesters out in force after months of turmoil: In pictures Show all 32 1 /32 Hong Kong protesters out in force after months of turmoil: In pictures Hong Kong protesters out in force after months of turmoil: In pictures A protester throws a stone into a building at Hong Kong Polytechnic University on 11 November Reuters Hong Kong protesters out in force after months of turmoil: In pictures Police patrol the streets of Hong Kong the day after an officer shot a protester during a protest on 11 November EPA Hong Kong protesters out in force after months of turmoil: In pictures Riot police stand guard during a protest against police brutality in Hong Kong on 27 October EPA Hong Kong protesters out in force after months of turmoil: In pictures Protesters carry traffic cones to build a barricade during anti-government protests in Causeway Bay, Hong Kong on 11 November Reuters Hong Kong protesters out in force after months of turmoil: In pictures Protesters use obstacles and bricks to block a road in Hong Kong on 11 November AP Hong Kong protesters out in force after months of turmoil: In pictures Graffiti on a window smashed by student protesters in Hong Kong Polytechnic University AP Hong Kong protesters out in force after months of turmoil: In pictures Protesters carry US and British flags during a demonstration in Hong Kong on 11 November Reuters Hong Kong protesters out in force after months of turmoil: In pictures A protester throws a bottle of water as he is shrouded in tear gas during a demonstration in the Tsim Sha Tsui district of Hong Kong on 27 October Reuters Hong Kong protesters out in force after months of turmoil: In pictures Journalists take pictures of police officers as they move to disperse protesters in Hong Kong on 27 October Reuters Hong Kong protesters out in force after months of turmoil: In pictures An man lies injured after being attacked by protesters who suspected him of being an undercover police officer on 27 October EPA Hong Kong protesters out in force after months of turmoil: In pictures A man runs among tear gas during a protest in Hong Kong on 27 October Reuters Hong Kong protesters out in force after months of turmoil: In pictures Protesters gather on a field in the Tsim Sha Tsui district of Hong Kong on 27 October Reuters Hong Kong protesters out in force after months of turmoil: In pictures Pro-democracy protesters turn away from a fire lit outside the Causeway Bay Mass Rapid Transit (MTR) station in Hong Kong on 4 October Getty Hong Kong protesters out in force after months of turmoil: In pictures People rest near rows of riot police officers during a protest in Mong Kok, Hong Kong on 27 October Reuters Hong Kong protesters out in force after months of turmoil: In pictures Pro-democracy protesters hold umbrellas as police fire tear gas at them ouside Tai Koo MTR station in Hong Kong on 3 October Getty Hong Kong protesters out in force after months of turmoil: In pictures Hong Kong police fire a water cannon from the central government office at protesters during a mass rally on the 70th anniversary of the founding of communist China on October 1 AFP/Getty Hong Kong protesters out in force after months of turmoil: In pictures Protesters burn a Chinese national flag during a mass rally on the 70th anniversary of the founding of communist China on 1 October AFP/Getty Hong Kong protesters out in force after months of turmoil: In pictures Protesters remove signs celebrating the 70th anniversary of the founding of communist China during a mass rally in Hong Kong on 1 October AFP/Getty Hong Kong protesters out in force after months of turmoil: In pictures Cardboard boxes set alight by protesters burn in the streets of Hong Kong during a mass rally on the 70th anniversary of the founding of communist China on 1 October EPA Hong Kong protesters out in force after months of turmoil: In pictures An anti-China banner has been placed in a barricade during a mass rally on the 70th anniversary of the founding of communist China on 1 October EPA Hong Kong protesters out in force after months of turmoil: In pictures A pro-democracy protester runs away after police fire a tear gas canister in Hong Kong's Wong Tai Sin district on October 4 Reuters Hong Kong protesters out in force after months of turmoil: In pictures Protesters run after police fire tear gas during a mass rally on the 70th anniversary of the founding of communist China on 4 October AFP/Getty Hong Kong protesters out in force after months of turmoil: In pictures Pro-democracy protester take cover after police fire a tear gas canister in Hong Kong's Wong Tai Sin district on 4 October Reuters Hong Kong protesters out in force after months of turmoil: In pictures The rally comes after months of protests on the streets of Hong Kong which began in oppposition to a proposed extradition bill EPA Hong Kong protesters out in force after months of turmoil: In pictures The extradition bill would have allowed the government to extradite people to China if they were facing certain criminal charges AFP/Getty Hong Kong protesters out in force after months of turmoil: In pictures Opposition to the bill stems from the fear that the Chinese government would abuse this power for political or commercial reasons EPA Hong Kong protesters out in force after months of turmoil: In pictures Protesters soon came to demand greater freedom and universal suffrage under the One Country, Two Systems principle AFP/Getty Hong Kong protesters out in force after months of turmoil: In pictures Protesters are wearing black to symbolise opposition to China as they take to the streets in a "day of grief" while the Chinese state celebrates the 70th anniversary of its communist founding AFP/Getty Hong Kong protesters out in force after months of turmoil: In pictures A protester charges forward holding umbrellas as a mass rally breaks out in violence in Hong Kong on 1 October AFP/Getty Hong Kong protesters out in force after months of turmoil: In pictures A protester pours water on a tear gas canister fired by police during a mass rally on the 70th anniversary of the founding of communist China on 1 October Reuters Hong Kong protesters out in force after months of turmoil: In pictures A protester carries a vandalised Chinese flag through Hong Kong during a mass rally on the 70th anniversary of the founding of communist China on 1 October EPA Hong Kong protesters out in force after months of turmoil: In pictures Protesters carry a banner that denounces the celebration of the 70th anniversary of the founding of communist China on 1 October EPA

Clashes broke out across at least five locations on Tuesday as tens of thousands denied a protest ban to take to the streets, aiming to embarrass Beijing as it celebrates the 70th anniversary of the founding of communist China.

Police have opened fire with tear gas and water cannon in several places, and protesters have started a number of fires.

The city's Hospital Authority confirmed one person was in critical condition at Princess Margaret, and that 15 had been injured in total during the violence between protesters and police.

Hong Kong police fire tear gas and a water cannon at protesters on China's 70th anniversary

The unrest has caused a near-complete shutdown of the city's MTR metro system and lead to urgent warnings from the government for protesters to evacuate the area around the main Legislative Council headquarters.

Planned events to mark China's "National Day" in Hong Kong had already been scaled down or cancelled, with police warning that they anticipated the situation would be "very, very dangerous".

The Civil Human Rights Front, a group that has organised some of the largest rallies of recent months, said it wanted protesters to treat the 70th anniversary as a "day of grief", urging protesters to dress in black.

Organisers said at least 100,000 people marched along a broad city thoroughfare in defiance of a police ban, chanting anti-China slogans and some carrying Chinese flags defaced with a black cross.

Many demonstrators tossed wads of fake "hell" bank notes usually used at funerals into the air. "The leaders who won't listen to our voice, this is for them," marcher Ray Luk told the Associated Press.

"Today we are out to tell the Communist Party that Hong Kong people have nothing to celebrate," said activist Lee Cheuk-yan as he led the central march.

"We are mourning that in 70 years of Communist Party rule, the democratic rights of people in Hong Kong and China are being denied. We will continue to fight."

Activists carried banners saying "End dictatorial rule, return power to the people".

The protests contrasted dramatically with military and civilian parades presided over by President Xi Jinping in Beijing.

The city's anniversary festivities included a tightly choreographed - and high-security - display of military hardware, some of it believed to be new ballistic missile technology.

As floats went by representing 56 regions and ethnicities from across the nation, 70,000 balloons were released - alongside 70,000 doves of peace. Later, a major fireworks display will be held in honour of the People's Republic's birthday.

Hong Kong chief executive Carrie Lam, who was in Beijing for the ceremony, smiled as a Hong Kong float passed by.