The Hong Kong protests escalated on Tuesday as the police said activists threw acid on officers and, separately, the police used live rounds for the first time and shot an activist.

The two incidents happened about 12 miles apart but show an escalation on both sides.

"Rioters have used corrosive fluid in Tuen Mun area, injuring multiple Police officers," the Hong Kong Police Force tweeted alongside images of what it said was an officer with chemical burns.

The Hong Kong Police Force said an officer shot a protester in the chest in the Tsuen Wan district.

Tuesday is China's National Day, the 70th anniversary of China's Communist Party. It's a major national celebration.

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The Hong Kong protests escalated on Tuesday as a police officer shot a protester with a live round for the first time in 17 weeks of demonstrations and the police said officers were doused in acid.

The protests on Tuesday, which coincided with China's National Day and the 70th anniversary of the ruling Communist Party, turned dark amid multiple clashes around the city.

The police shot a man in the chest in the city's Tsuen Wan district, The Associated Press reported, citing police officials. It marked the first time the police have used live rounds during the 17 weeks of protests.

A video posted on Facebook shows a protester in Hong Kong lying on the road with a bullet wound to the chest. Facebook/香港城市大學學生會編輯委員會

A video posted on Facebook showed a protester with a wounded chest lying on the ground, asking to be taken to a hospital.

In a separate confrontation, protesters used an acid-like substance on police officers, the Hong Kong Police Force said. It posted images of an officer's burns on Twitter.

A map of where the police said protests threw acid at officers and where the police shot a demonstrator in the chest with live ammunition. Google Maps

The tweet said: "Rioters have used corrosive fluid in Tuen Mun area, injuring multiple Police officers and reporters.

"The Police strongly condemn the violent acts and appeal to members of the public to mind their personal safety."

—Hong Kong Police Force (@hkpoliceforce) October 1, 2019

The New York Times also reported that "seven masked men used a Molotov cocktail to burn posters of Xi Jinping outside a Chinese Army barracks" on Tuesday.

The escalations came at a symbolic time in China. Tuesday marks 70 years since the Chinese Communist Party under Mao Zedong seized control of the country during a bloody civil war.

Members of a Chinese military honor guard march during the Tuesday's celebration in Beijing to commemorate the 70th anniversary of the founding of Communist China. AP Photo/Ng Han Guan

The milestone was commemorated by a huge parade in Beijing's Tiananmen Square, featuring a show of military might from the People's Liberation Army.

A Chinese Ministry of Defense spokesman, Maj. Gen. Cai Zhijun, said last week, according to the AP, that the parade would comprise 15,000 troops, 580 pieces of military equipment, and more than 160 fighter aircraft.

At the parade, China after weeks of speculation unveiled the Dongfeng 41 missile, believed to be the world's longest intercontinental weapon and capable of striking targets 9,320 miles away.

The Dongfeng 41, a nuclear-capable intercontinental ballistic missile. Getty

In a post on Facebook on Saturday, the Hong Kong edition of the Chinese state newspaper China Daily said that Hong Kong "anti-government fanatics" were "baying for blood" ahead of the celebrations.

Protesters on Tuesday marched 2 1/2 miles from Causeway Bay to Central, Bloomberg reported. Figo Chan, a leader in the Civil Human Rights Front organizing group, said that more than 100,000 people marched.

The Hong Kong Police Force on Monday said protests planned in the city were expected to be "very, very dangerous" and claimed that hardliners had called on people to kill police and set fire to gas stations. As Business Insider's Rosie Perper reported, the police's chief superintendent, John Tse Chun-Chung, gave no evidence to substantiate the claims.

Read more: Protesters in Hong Kong may have almost won this battle — but the fight for freedom and identity is far from over