China’s military carried out drills along the border with Burma on Tuesday, in a show of force to highlight its resolve to protect its people, state news agency Xinhua said, following clashes between Burmese security forces and ethnic rebels.

Fighting this month in Burma pushed thousands of people into China to seek refuge, prompting Beijing to call for a ceasefire between ethnic militias and the security forces.

Xinhua said the joint land and air exercises were part of planned annual drills, but did not say exactly where they took place.

It quoted a Chinese army colonel as saying the exercises showed “the People’s Liberation Army’s resolute resolve” to protect the security of the border and the lives of residents there.

In accordance with existing agreements, China informed Burma’s military ahead of the drills, it added.

China has repeatedly expressed concern about fighting along the border that has occasionally spilled into its territory, for instance in 2015, when five people died in China.