China is hosting lavish events to mark 70 years since the founding of the People's Republic of China (PRC).

On 1 October 1949, Mao Zedong - or Chairman Mao - announced the formation of the PRC, after communist forces won a bloody civil war. Modern China has since developed at an extraordinary pace, but it has also one of the world's most restrictive states. One of the biggest military parades ever is currently under way, with President Xi Jinping expected to speak. Fifteen thousands troops are filling Tiananmen Square in central Beijing, and the nation's newest military technology is on display. The celebrations on Tuesday risked being overshadowed by ongoing protests in Hong Kong, where thousands of people were expected to take to the streets in protest against what they say is increasing control by Beijing over the territory's society and politics. Police said they had received credible intelligence that activists were planning a major violent escalation, setting fire to shops and train stations. Hong Kong was in lockdown in the early hours of Tuesday, and some 6,000 officers were deployed in the territory. Several metro stations and shopping centres were closed. An annual fireworks display had previously been cancelled.

What is China celebrating?

Seventy years ago, Chairman Mao announced the birth of the PRC after the Communist Party of China defeated the ruling Kuomintang (KMT) - or National Party. The two sides had been locked in a costly civil war since the 1920s, after the collapse of the imperial system. The events would show that China had "stood up, grown rich and become stronger over the past decades", officials said. "The main theme is to tell Chinese stories and express the Chinese people's confidence in the party and the country," said Zhang Ge, one of the officials responsible for the anniversary celebrations. China has said it is developing an entirely new political system - "socialism with Chinese characteristics" - and that it has raised millions out of poverty. To its critics though, China is a deeply oppressive country turning back progress on global human rights. It has been widely criticised for its lack of democracy, suppression of rights and any sign of dissent, an unfair justice system with a 99% conviction rate, and in recent years the mass detention of ethnic Uighur Muslims in Xinjiang, among other groups.

What will the military parade involve?

Huge amounts of weaponry will be on display, including army vehicles and domestically made missiles and launchers. More than 150 aircraft - including stealth jets and strategic bombers - will fly in formations over the capital. That will be followed by what officials are calling a "happy and lively show" involving about 100,000 civilian performers on floats, from farmers and teacher to doctors and students. And then in the evening a gala performance will be held in the square. The events are open to officials, select members and invited foreign dignitaries only, but they will be watched by hundreds of millions of people around the country. Security has been high in central Beijing for weeks - there are strict controls on flying kites or drones around the parade area. Even racing pigeons have been banned. Media censorship - always stringent in China - has been tightened even further, with broadcasters given a set list of programmes to play and internet censors removing any online criticism of the Communist Party or its leaders.

What is happening in Hong Kong?

Hong Kong has been a part of China since 1997 but has its own system of law and government - known as One Country Two Systems. In a speech given on the eve of the 70th anniversary celebrations, President Xi maintained to "fully and faithfully implement" the principles of this system. But in recent years, there has been increasing opposition to what has been seen as the growing influence of Beijing on Hong Kong's society and politics. Hong Kong always sees anti-Beijing protests on 1 October, and this year they are expected to be larger than ever, because of the months of unrest triggered by proposed changes to the extradition law. The changes would have made it possible for China to extradite people to the mainland from Hong Kong, something opponents felt put Hong Kongers at risk of persecution in unfair trials. For nearly four months, protesters have taken to the streets - at times in the millions. The proposed changes to the extradition law have officially been scrapped but that has failed to quell the unrest which has now evolved into an existential battle over Hong Kong's future. The protesters are now demanding full democracy for the territory and for police to be held accountable over the use of force, among other issues. Carrie Lam, Hong Kong's leader, will be in Beijing on National Day. BBC