Crowded streets, angry protesters, riot police and clouds of tear gas. This is the scene in Hong Kong as tens of thousands of pro-democracy protesters occupy the heart of the region and clash with police.

What started as a peaceful protests against China's recent moves to curtail free elections in the region quickly turned chaotic Sunday as Hong Kong police used tear gas and pepper spray to disperse the crowds.

The police crackdown has outraged many in Hong Kong, and the region is now facing mass civil disobedience on an unprecedented scale. No one's quite sure how these protests will turn out.

Despite being nominally ruled by totalitarian China, Hong Kong is no stranger to public demonstration. The current unrest was preceded by weeks of student protests and planned rallies demanding China loosen its grip on Hong Kong's elections. (Video via CNN)

>> Read more trending stories

And public outcry has even managed to affect social change in the past: two years ago, a proposed pro-Communist education plan was withdrawn after student protesters occupied Hong Kong's government headquarters.

But previous protests haven't reached this level of violence, and the escalation has some analysts bringing up an earlier pro-democracy movement which challenged China's authority.

This year marked the 25th anniversary of the Tiananmen Square protests, when student protesters in Beijing were brutally suppressed by the Chinese military. The crackdown drew severe condemnation from the West but also effectively crushed the country's democracy movement. (Video via ABCNBC)

So far, Beijing's made no mention of military intervention in Hong Kong. The government has labeled the protests illegal and refused to budge on any of the protester's demands, according to state-run media.

China's censors have also blacked out any reference to the protests online, which, as Foreign Policy reports, has led to a blanket ban on Instagram in order to prevent the spread of protest images.

As a Vox writer points out, China can't afford to remain passive on this debate; a win for the protesters could fundamentally change the relationship between China and Hong Kong.

"Both the pro-democracy protesters and Beijing are hoping to force Hong Kong's public to choose whether or not to accept ... China's growing control over Hong Kong politics. ... If Hong Kong residents join the protesters en masse, they will be rejecting not just the 2017 election terms, but the basic terms of Hong Kong's relationship with the central Chinese government."

The protests were sparked by China's announcement in August that any candidates for Hong Kong's elections would be screened by a pro-China committee. Protesters are calling on Hong Kong's central government to reject the framework of the region's 2017 elections, a demand Hong Kong's leaders have repeatedly denied.

This video includes images from Getty Images.