HONG KONG (AP) — Chinese state media has published photos of the country's Hong Kong-based troops' armored carriers and a patrol boat undertaking what they call a routine rotation.

State news agency Xinhua said the 22nd rotation of the People's Liberation Army's Hong Kong garrison took place in the early hours of Thursday.

Nearly three months of fiery pro-democracy demonstrations in Hong Kong have sparked concerns that the military will be deployed in the semi-autonomous Chinese city. The Hong Kong garrison previously published a promotional video with scenes of soldiers facing off with people dressed like protesters.

Xinhua said the soldiers in the new rotation were educated on Hong Kong's laws and vowed to defend the nation's sovereignty. Troops stationed in Macao, another special administrative region, also completed a rotation Thursday.