Clashes have intensified in large areas of Myanmar's northern Shan state, close to the Chinese border, forcing more than 80,000 people to leave their homes, according to the United Nations.

An armed alliance of ethnic minority groups in October launched a major offensive against the army in regions close to the Chinese border, displacing more than 332,000 people, the United Nations has said.

The groups have seized dozens of military positions and a town that is important for trade with China.

Against this backdrop, the Chinese army has launched "combat training activities" along the border with Myanmar, Beijing's Southern Theatre Command said Saturday in a statement that did not specify the duration of the exercises or the number of soldiers involved.

The aim of the drills is to "test the ability of troops... to control and close borders and to strike with firepower", the army said, adding that it was "ready to respond to all kinds of emergencies".

Beijing informed Myanmar's ruling junta about the exercises, junta spokesman Zaw Min Tun said Saturday, adding the military would "cooperate with China to work for peace and border stability".

On Friday, state-owned Myanmar media reported that the military's opponents had used drones to drop bombs on vehicles in Muse, a border town opposite China's Ruili city.

The attack, which took place on Thursday, destroyed 120 vehicles "carrying household goods, consumer goods, clothing and construction materials", according to the Global New Light of Myanmar.

A significant proportion of Myanmar's trade with China transits through this region.

The blockage of the trade route has dented the junta's finances, compounding the economic problems the military has faced since the 2021 coup.

China called on Friday for its citizens to leave northern Myanmar "as soon as possible" and to stay away from the fighting.