Images broadcast Thursday showed the country’s troops entering Hong Kong in what Chinese state media said was a “routine rotation” to replace soldiers at the People’s Liberation Army (PLA) garrison in the semi-autonomous territory. However, the images are likely to add to fears of an imminent Chinese military intervention in Hong Kong’s political crisis.

In the images broadcast by state media, troops can be seen crossing the border into Hong Kong from the mainland in trucks and armoured personnel carriers, as well as disembarking from a Chinese navy vessel.

"Before coming to Hong Kong on rotation, we studied systematically at a mainland base to learn about the situation in Hong Kong and relevant knowledge about the law,” said Yang Zheng, battalion commander at the PLA Hong Kong garrison.

“At the same time, we have strengthened military training and improved combat ability to make sure we can fulfill the defence duty."

China has an estimated 8,000 to 10,000 troops stationed at its Hong Kong garrison who have so far remained confined to barracks amid the ongoing pro-democracy protests that have gripped the territory over the past three months.

But fears of Beijing launching a military intervention have risen in recent weeks after state media released videos showing Chinese troops massing near the Hong Kong border and PLA soldiers at the Hong Kong barracks undergoing what Beijing said were “anti-riot drills”.