Hong Kong police used live ammunition for the first time during pro-democracy protests on Sunday.

An image of one man facing an officer's gun with his arms outstretched is being compared to Tianenman Square's "tank man," who stopped before a column of tanks sent to quell pro-democracy protests there in 1989.

Hong Kong police made dozens of arrests, including of a 12-year-old boy, as pro-democracy protests stretched into their 12th week.

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Ongoing protests in Hong Kong have turned violent as police fired live ammunition and pointed firearms at protesters on Sunday — including at one man now being dubbed "pistol man," after 1989's infamous Tiananmen Square "tank man."

After a period of relative calm, including a peaceful protest Friday modeled after 1989's Baltic Way pro-democracy protests where protesters linked arms in a chain that stretched for 37 miles, Hong Kong police fired the first live ammunition of the 12-week protest period, and used water cannon vans for the first time ever in Hong Kong against protesters, CNN reported.

A group of protesters broke away and hurled Molotov cocktails.

Clashes between protesters and the police began in the Tsuen Wan area around 8:00 PM local time Sunday, according to the Hong Kong Free Press. A group of protesters broke away from the main, police-approved protest and threw Molotov cocktails from behind a makeshift barricade, according to CNN. The protesters chased the police with metal pipes, according to the South China Morning Post, and had smashed shop windows in the area.

Six police officers drew their firearms against protesters and reporters, and one fired a warning shot into the air. No injuries were reported from the warning shot.

Read more: Hong Kong will become another Tiananmen Square if China's army comes, a protest leader warns

Hong Kong's 'tank man' tried to keep the police from shooting.

In the middle of this chaotic scene, police kicked a civilian, a man in a tank top who appeared to put his body between the police and the protesters to prevent police from shooting. Some activists have compared the man to the Tiananmen Square "tank man" after Hong Kong news outlet RTHK captured video of him kneeling before police as they attempted to advance on protesters with weapons drawn.

—Joshua Wong 黃之鋒 (@joshuawongcf) August 26, 2019

A police spokeswoman defended kicking the kneeling man as 'a natural reaction.'

Senior Superintendent Yolanda Yu, a spokesperson for the Hong Kong Police Public Relations Branch, told reporters, "Six officers drew their service weapons because their lives were under threat… to protect themselves, other officers and people at the scene. One officer fired a warning shot into the air, which did not hit anyone."

"The officer acted heroically and with restraint, and the force used under the circumstances was necessary and reasonable," Yu said, according to the Hong Kong Free Press.

When asked about the man who was kicked while standing between the protesters and the police, Yu said, "This was a natural reaction" to the circumstances.

But the violence concerned some activists.

"No one died yet, but with police's attitude like that I fear something more horrible may happen soon," Bonnie Leung, the Vice Convenor of the Civil Human Rights Front, told Insider.

Hong Kong police also made dozens of arrests on Sunday, including a 12-year-old boy, according to NPR.