Hong Kong belongs to China, but has its own currency, political system and cultural identity. Many Hong Kong residents are not considered Chinese, but rather Hong Kong.
This difference goes back generations; the city was a colony and territory of the United Kingdom for more than 150 years until the British handed it back to China in 1997. Today, Hong Kong's legal system still reflects the British model, appreciating transparency and due process.
A policy called "one state, two systems" reinforces this uniqueness. According to the policy, Hong Kong maintains a de facto constitution known as Hong Kong's basic law. It guarantees freedoms not accessible to mainland Chinese, such as the right to protest, the right to free press, and freedom of expression.
One of the principles of the basic law is that Hong Kong has the right to develop its own democracy, and previous Chinese officials have promised that the Beijing central government will not interfere. But in recent years, Beijing has repeatedly interpreted the Basic Law ̵
The Basic Law states that Hong Kong will "protect the rights and freedoms of residents" for 50 years after the transfer. But many residents say that mainland China is already beginning to encroach on these rights.
This perceived threat to the rule of law in Hong Kong has led to regular confrontations in which hundreds of protesters have been arrested so far.
What do protesters want?
The protests began in March, but began in earnest in June. They were prompted by widespread opposition to the extradition bill that had already been repealed, but have since expanded to full democracy and accountability for the police.
Because the protest movement is without a leader, not everyone has the same purpose in mind. But overall, five basic demands have emerged: to withdraw the bill in order to withdraw leader Kari Lam, an investigation into police brutality, to release the arrested and greater democratic freedoms.
Why are protesters heading to the airport?
Many activists have come to view the Hong Kong International Airport as something like a safe protest space away from the streets where clashes between protesters and police have become commonplace.
But that may have changed on Tuesday night after police made their first significant appearance at the airport since the protests began there five days ago.
The airport, one of the busiest in Asia, emerged as a key target of protest as anti-government demonstrators appeared to convey their message directly to the international community.
At the airport, last weekend, leaflets in Chinese, English, French, Korean, Japanese and other languages were distributed to arriving international visitors, explaining the causes of the unrest – as protesters see it – and the demands of the opposition movement.
The display of the elegant design characterizing the protests, other pamphlets and posters also advertised the planned demonstrations as "new tourist sites". and advises tourists what to do if they are caught up in the protests during their visit.
Nearly 1,000 flights were affected by the protests on Monday and Tuesday, according to the executive director of the Hong Kong Airport. The court then issued an order restricting people's access to the airport.
What does this mean for Hong Kong's economy?
While mainland China is Hong Kong's most important trading partner, the city is an international business and financial hub and the economy is already showing signs of injury as a result of the protests.
The companies are already reporting "serious consequences of the outage", including lost revenue, broken supply chains and cutbacks, the US Chamber of Commerce in Hong Kong said last month.
Hong Kong businesses, both international and local, also face pressure and accusations of acting in concert or sympathizing with protesters. Chinese aviation authority Cathay Pacific, a leading Hong Kong carrier and major local employer, has been ordered to ban protesters from traveling to China.
The airport contributes 5% to Hong Kong's GDP, directly and indirectly, said Frank Chan, Hong Kong's secretary of transportation , In May.
What does the government say?  Officials in both Hong Kong and Beijing are increasingly critical of the protests.
In a statement issued early Wednesday morning, Hong Kong police denied the "radical and violent actions of protesters" at the airport, and a government spokesman described the incident at the airport as exceeding the "bottom line of civilized society".
In China, the coverage of protests has shifted from censorship to focus on clashes and riots, with protesters labeled "violent mafia" and "criminals". On Monday, Yang Guang, spokesman for the Hong Kong-Macao Office, China's top city affairs body, said the protests show "signs of terrorism" and suggest they pose a real threat to the rule of law .
"Hong Kong radical protesters have repeatedly attacked police officers with extremely dangerous tools," he said. "They have already committed serious crimes of violence and have begun to show signs of terrorism. This is a gross violation of the rule of law and social order in Hong Kong, which threatens the life and safety of Hong Kong citizens."
The escalating rhetoric has raised concerns that China may be considering strong intervention.
In an interview with CNN, Max Baucus, former US ambassador to China, described the challenge that protesters face to the central government of China "
" If Beijing thinks it can just clog the protesters' throats, it won't work. I think they know this and are trying to find a way out, "he said.
"Remember. China is very conservative. It is difficult for China to handle such things – they are used to having their own way. It is difficult for them. They are not agile. They are not" I do not have a large diplomatic core as for example, the United States. That's hard for them. "
What do other countries say?
US President Donald Trump called for calm on Twitter on Tuesday afternoon. He said US intelligence shows" the Chinese government is moving troops to the Hong Kong border . Everyone has to be calm and safe! "China already maintains a troop presence near the Hong Kong border.
Meanwhile, British MPs have expressed concern about the worsening situation. Foreign Affairs Committee of the House of Commons Lunch Yenin said on Tuesday that the UK should consider extending "full Chinese citizenship rights to the Chinese."
"This should have happened in 1997 and is a mistake that needs correction," Tugendhat Tweet .
United Kingdom Foreign Minister Dominic Raab says he is concerned about "what is happening in Hong Kong and disturbing photos of clashes between police and protesters at the airport" on Tuesday.
"As I told Kari Lam during my talk last week, we condemn the violence and encourage constructive dialogue to find a peaceful way forward," Raab tweeted. CNN's Jill Dissis, Sheris Pham and Laura Hee, Doug Chris, Sarah Dean, Ben Westcott, Julia Hollingsworth, James Griffiths, Steve George and Helen Regan contributed to this report.