As China marks 70 years of Communist rule with lavish celebrations, others are raising concerns about the lack of freedom in the country.

Events have been taking place throughout Tuesday to commemorate the formation of the People's Republic of China by Mao Zedong on 1 October 1949, ending years of brutal civil war.  

The pinnacle of the national day celebrations was a military parade in Tiananmen Square in which thousands of military personnel took part.

In a display of might, military vehicles made their way through the square as part of the parade, alongside grand floats and traditional Chinese lion dancers. 

In a brief opening address, President Xi Jinping said that "no force" could stop China's forward march. 

"No force can ever stop the Chinese people and nation from marching forward," he said. 

In Hong Kong, the scene of heated protests over fears of Beijing interference, the mood was more sombre as thousands defied a police ban to march through the city on the anniversary.

Benedict Rogers, East Asia Team Leader at Christian Solidarity Worldwide, said: "Many people in China are not celebrating. And certainly anyone, in or outside China, who believes in freedom and human dignity, has nothing to celebrate on this 70th anniversary." 

Yaqiu Wang, China researcher at Human Rights Watch, tweeted: "Today is the 70th anniversary of the Chinese Communist Party's rule of China. The CCP killed tens of millions of Chinese people, plundered our resources, forbids us from speaking our mind, and jails us if we criticize it, thus is arguably the biggest anti-China org in the world."

Many comments of opposition were being posted to Twitter on Tuesday with the hashtag #NotMyNationalDay. 

While China has seen astonishing economic growth and development in recent years, it continues to exercise tight control over what its citizens can believe and the information they can access, with Facebook, Twitter and Google all banned. 

Citizens who openly challenge the state face arrest and detention.  Christians, too, face restrictions on the practice of their faith, with China requiring churches to be registered. 

'Underground' and house churches that refuse to do so face police harassment, raids and closure.  Since Xi's ascent to power, the Communist Party's ideological grip on official churches has tightened, with some recently reporting that they were told to replace the Ten Commandments with quotes by the president. 

China Aid, which monitors religious freedom in China, reports that official Catholic churches in the country were instructed to celebrate the Communist Party's leadership over the last 70 years by singing the national anthem and raising the Chinese flag before mass in the run-up to National Day. 

One Christian from Fujian province told China Aid that his church had held patriotic singing competitions as part of National Day celebrations.

"Churches across the country are forced to participate in singing patriotic songs, which is very ridiculous because patriotic songs basically are linked with the chaotic era of the Cultural Revolution," he said. 

Open Doors, which supports persecuted Christians worldwide, ranked China 27th in its 2019 World Watch List of the top 50 countries where Christians suffer most for their faith. 

David Curry, President and CEO of Open Doors, told Mission Network News last month that the Church in China was coming under increased pressure. 

"China has moved up [the World Watch] list unfortunately and it has to do with the growing, increasing pressure on house churches — what has typically been underground churches," he said. 

"That is a little misleading because they're typically well-known within their communities. But [there is] growing pressure to register these house churches.

"The government has been pressuring [house churches] and then when they register, they have been monitoring them in a little more official way, a little more onerous way."

He continued: "If they allow Christians to exist, they want that Christian faith to be 'Chinese' or loyal to the government to validate government politics [and] policy. 

"The Chinese Church is wary of doing that because, of course, this nationalization of the Church means they may one day be forced to choose between Jesus and the Chinese government."