On October 1, despite a police ban, tens of thousands of protesters filled the streets of Hong Kong, and the demonstrations quickly clashed with police.

The day marks 70 years since the People's Republic of China was founded, but protesters in Hong Kong were calling it a "national day of mourning."

The demonstrations began in June to fight a bill that would extradite people accused of crimes to China to stand trial, but since then the protests have not relented, and the protesters demands have widened.

The violence of the protests is also escalating — a policeman had acid thrown on him and an activist was shot with live rounds.

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Tens of thousands of people ignored a police ban and protested in Hong Kong on Tuesday, the day China was celebrating 70 years as the People's Republic.

Protesters, dressed in black, called it a "national day of mourning." Some vandalized buildings, and threw petrol bombs and rocks at the police. The police fought back — one protester was shot by a live round, and is thought to be in critical condition.

It was the largest number of simultaneous protests since June, when the demonstrations began to fight an extradition bill that would have allowed people accused of crimes to be extradited to China to stand trial. Protests have continued over the months and they now have five demands, which include introducing free and fair elections in Hong Kong.

Here's what the day looked like on the ground.