Dozens of Chinese military vehicles entered Hong Kong on Thursday morning for what state media called a "routine rotation" of its officers stationed in Hong Kong.

Chinese state media reported on the movements as it was happening — a contrast to previous years where they publicized the rotation of troops only after it had occurred.

China has maintained a military presence in Hong Kong since its handover from British rule in 1997, but has never utilized the army to intervene in local affairs.

Experts say China may be signalling that it's prepared to use force to quell increasingly violent protests in Hong Kong.

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Dozens of Chinese military vehicles entered into Hong Kong in the early hours of Thursday morning for a "routine rotation" of its members in its Hong Kong arm, state media claimed.

Chinese state media on Thursday released videos and photos of the military movement as it was occurring, a move which stood in contrast with previous rotations which were reported on only after they were completed.

State news agency Xinhua reported that the military trucks rotated members of the People's Liberation Army (PLA) Hong Kong Garrison at around 4 a.m. on Thursday.

The PLA has maintained a military presence in Hong Kong since Britain handed over the city's sovereignty to China in 1997, and quietly rotates its members every year.

People's Daily China, the Communist Party's mouthpiece, tweeted a video of the exercises, stressing that the move was a "normal routine annual rotation" and in line with Hong Kong's mini constitution, known as the Basic Law.

The Basic Law guarantees Hong Kong a high degree of autonomy from China, including a separate legal and judicial system.

It also stipulates that the PLA Hong Kong Garrison — composed of personnel from China's navy, ground, and air forces — can intervene in Hong Kong affairs if the local government calls on the military arm for the "maintenance of public order," or if China's Standing Committee decides Hong Kong is in a state of emergency.

"[The troops] are determined to resolutely protect national sovereignty, security and development interests," Xinhua said in its reporting of Thursday's troop rotation, according to the South China Morning Post.

"They will effectively carry out the duty of defending Hong Kong, and perform more new contributions to maintaining the prosperity and stability of Hong Kong."

Hong Kong residents also posted videos of the movements on social media, showing dozens of military vehicles crossing the border in Huanggang Port, the vehicular border crossing between Hong Kong and Shenzhen, southern China.

China may be signalling the country's readiness to combat protests with force, experts say

Despite China's attempts to portray the movement of military troops as routine, experts say China may be signalling that it is prepared to use force to quell the increasingly violent protests in Hong Kong. The demonstrations are now in their 12th week.

Bill Bishop, who publishes the Sinocism China Newsletter, tweeted that he was skeptical that these Chinese military movements were just a "routine rotation."

According to Bishop, Xinhua's 2018 announcement of the rotation specified that the number of troops and equipment brought in remained the same as the year prior. That same language was notably absent from this year's announcement, Bishop said.

China has repeatedly signaled that it's prepared for military intervention in Hong Kong, and has been gathering troops at the Hong Kong border in recent weeks.

Read more: Hostile protests in Hong Kong are unlikely to end anytime soon unless world leaders address Chinese interference, activists say

Chinese military troops march during a welcoming ceremony for US President Donald Trump during his Asia trip in November 2017. Thomas Peter-Pool/Getty Images

But while China has indicated it is ready to use force, doesn't mean it necessarily will at this point.

Experts remain skeptical that Chinese military intervention in Hong Kong is imminent, and say recent displays are part of a wider strategy aimed at intimidation and deterrence.

Adam Ni, a China researcher at Macquarie University in Sydney, told Business Insider that while Beijing may at some point choose to use ground force, Chinese intervention isn't imminent because the risks of such a move are too high at this stage.

"Beijing is trying to deter escalating protests by signaling that it's determined to intervene with military force if necessary," Ni said.

"But the complexity, as well as the risk of such an operation, is so high at this point that it's just not worth it to the leadership in Beijing."