The barricades were meant to keep them out, but protesters have instead turned this around: BBC cameraman Joe Phua tweeted this out:

Taiwan President Tsai Ing-wen has posted a picture on Instagram saying "Taiwan supports Hong Kong!"

In her caption, Ms Tsai said: "Freedom is a value that the people of Taiwan cherish. Taiwan is liberalising and democratising while Hong Kong is losing its freedom."

She added that many young people from Hong Kong have reached out to her on Facebook, hoping to see support and solidarity from Taiwan.

"[We see their] thirst for human rights and democratic rule of law."

The roar of the crowds gathered in Hong Kong brings back memories of day one of the Umbrella Movement in 2014. The images are familiar too.

There are young people wearing surgical masks dragging iron barriers placed by the police in order to build their own barricade. The roundabout outside the Legislative Council Complex is filled with protesters.

Somebody threw a water bottle at police in riot gear guarding the entrance to the parliament and then they all stood up, waving their batons, shouting: "Who did that?"

Five years ago on the first night of the Occupy protest a similar scene erupted into chaos as police deployed tear gas canisters.

There have been no real clashes so far and protesters greeted the news that the debate had been postponed with jubilation. The council speaker gave no reason, but pro-democracy legislators told the crowd, that pro-Beijing colleagues just couldn't get in.

Postponing the meeting might defuse the situation for now, but nobody knows for how long - because the crowd is refusing to go.

Image source, EPA

In addition to wearing white on the streets, many Hong Kongers are also adding Bauhinia flowers - their national emblem - to their profile pictures on Facebook and Instagram to show unity and solidarity.

Many are also using the popular hashtag #NoExtraditionToChina, external on Twitter and other social media platforms.

After huge crowds proceeded through Hong Kong in protest against the law on Sunday, the government was swift to put out its response.

It pointed out the city's credentials as a "free, open and pluralistic society" that respected the right to exercise freedom of expression.

It went on to state that the bill was prompted by the murder of a Hong Kong citizen in Taiwan - and that none of the criminal offences relate to freedom of assembly, press, speech or publication.

It said Hong Kong's guarantee of judicial independence was not threatened by the bill.

"Executive and judicial safeguards built into the system protect all the human rights enshrined in the Basic Law and Hong Kong Bill of Rights Ordinance and ensure that any requests for assistance or surrender are legal, and subject to challenge and review up to the Court of Final Appeal."

There are large crowds of young people now blocking the streets to Hong Kong's Legislative Council Complex.

But this protest is notable for having united groups as diverse as students, lawyers and even big business. Many petitions are in circulation, including one from the former school of Hong Kong Chief Executive Carrie Lam. A group of housewives set up their own petition which collected thousands of signatures.

The government, all too aware of the scale of the opposition, has said that it has built in safeguards to answer critics concerns.

After Sunday, when Hong Kong saw the biggest protests since the former British colony was handed back to China, no-one was sure how many people would be out in the streets today.

But huge numbers have shown up.

Here are some scenes from the streets of Hong Kong as protesters wearing face masks and helmets engage in a standoff with police in riot gear.

Once one of Asia's biggest names in music, singer-turned Hong Kong campaigner Denise Ho is continuing to speak out against the controversial extradition bill. On Twitter, she tells her 200,000 followers that she is moved and "lost for words".

Over on Chinese social media site Weibo, there is - unsurprisingly- no mention of what's going on in Hong Kong today.

A quick search for the term "Hong Kong" only yields results about a recent table tennis tournament and train stations.

Another search for a Chinese phrase used by Hong Kong protesters to describe the anti-extradition movement also comes up blank.

Image source, Getty Images

Standard Chartered Bank has said it will temporarily suspend operations at its branches in the Admiralty area amid disruptions associated with the protests in Hong Kong, according to media reports.

China Citic Bank will also temporarily suspend operations in the area, South China Morning Post reported., external

Bank of East Asia said two branches near the Hong Kong protests will be closed until further notice, according to Reuters.

Hong Kong police are warning demonstrators not to throw bricks, after pictures emerged earlier showing protesters digging up bricks from the ground.

Today's scenes are reminiscent of the 2014 Umbrella Movement, where thousands marched for Hong Kong's right to choose its own leader.

Pro-democracy activist Nathan Law tweeted this picture today:

The BBC's Grace Tsoi in Hong Kong has posted this update from the Admiralty MTR (Mass Transit Railway) station.

The BBC's Stephen McDonell has posted images, taken by the newspaper South China Morning Post, of protesters digging up bricks from the ground.

The Twitterverse is abuzz with sightings of a young female protester, who was seen "meditating defiantly" in front of Hong Kong riot police.

And it wasn't long before her presence caught the attention of fellow demonstrators at the scene.

"Hong Kong, Hong Kong! Do you know this girl," asked Twitter user Kent Hwang.

"Bravery in the face of brutality. Beautiful," commented another.

Some even drew comparisons with the 1989 Tiananmen Square protests. "Thirty years ago, Tank Man stood his ground in Beijing. Today we have Shield Girl in Hong Kong," tweeted an observer. "Both of them have made their mark on Chinese history forever."

Here are just some of the dramatic images from Hong Kong today.

Protesters have hung umbrellas off the barricades - a nod to the pro-democracy Umbrella Movement demonstrations in 2014.

These are the city's largest rallies since 1997, when the territory was handed back to China by the British.

Image source, Getty Images

Image source, EPA

Image source, Reuters

These are some of the largest protests Hong Kong has ever seen.

The BBC’s Helier Cheung explains why the extradition bill is so controversial:

Hong Kong Police Force has tweeted that “this behaviour has gone beyond the scope of peaceful gatherings”.

“We call on [protesters] to leave as soon as possible… otherwise we will use appropriate force,” it added.

This is the start of our live page as tens of thousands of people in Hong Kong protest against a controversial bill that would allow the city to extradite people to mainland China.

The bill was due to have a second reading today, Wednesday, but the authorities have delayed it “to a later date” in response to the protests.

Huge crowds of protesters – some wearing face masks and helmets - have gathered in the centre of the city, and have blockaded the government headquarters and key roads nearby.

Police in riot gear have responded by using using pepper spray on demonstrators, and have said they are prepared to use force to disperse them.

Image source, AFP