Hong Kong — Four months of protests in Hong Kong reached a dangerous escalation when police targeted anti-government demonstrators with live ammunition for the first time. The crackdown came as China celebrated the 70th anniversary of its founding with a massive parade across Tian'anmen Square in Beijing, showing off its most advanced missiles to date — including one with the capability to hit anywhere in the continental United States.

For a time, Hong Kong resembled a war zone where pops of live ammunition echoed across the city's streets and as black smoke billowed from fires set by protestors in various districts.

During a brawl between a group of demonstrators and police, one officer shot a protestor in the chest at point-blank range. The 18-year-old student was left bleeding on the ground and screaming in Cantonese, "My chest is in pain. I want to go to the hospital."

He remains in critical condition. The police, once highly-respected, have called the shooting "lawful."

The incident ratchets up already-high tensions between protestors, police and the government since these protests began 17 weeks ago in June - sparked by a controversial extradition bill but which has since exploded into calls for universal suffrage and for Hong Kong's embattled chief executive, Carrie Lam, to step down.

"We are not fearful and we will continue to fight for our rights and I think it sends a very important message for the world to listen that Hong Kong people will continue to fight," Lee Cheuk-yan, a former pro-democracy legislator, told CBS News.

The protests have plunged Hong Kong into a yet unseen level of chaos. The government has responded by labeling protestors as "rioters," which automatically carries a longer prison term — a tactic that pro-democracy activists warn is just one step closer to declaring martial law.