China on Sunday condemned fighting on its border between Myanmar forces and ethnic rebels that has left 19 dead, mostly civilians, in some of the worst bloodshed on the restive frontier in recent years.
A local resident told AFP she heard gunfire through the night until early Sunday morning, with fear gripping a town that lives at the mercy of both government militias and ethnic armies fighting for more autonomy.
"We heard shooting the whole night until this morning around 6:00 am.... People are still frightened," said Aye Aye.
The insurgency in the northeast -- which is separate from the Rohingya crisis to the west -- is one of some two dozen ethnic minority rebellions that have roiled Myanmar's border regions since independence in 1948.
Observers believe Beijing holds significant sway over the rebels near its border with Myanmar and is a key player in Suu Kyi's faltering peace process.
On Sunday the Chinese embassy in Yangon condemned the clashes and said it had urged "relevant parties" to reach an immediate ceasefire.
The violence "made people from the Myanmar side flee across the Chinese border, and stray bullets have entered into Chinese territory", the statement added.
Clashes in the border region in early 2017 sent more than 20,000 Myanmar refugees scrambling across the border into China's Yunnan province, raising tensions between the neighbours.
Saturday's attacks were blamed on the Kachin Independence Army (KIA) and the Ta'ang National Liberation Army (TNLA), which claimed responsibility for the operation and apologised for the civilian deaths.
A TNLA spokesman told AFP its forces targeted a casino run by army-linked militias outside Muse.
Knut Ostby, the UN resident and humanitarian coordinator in Myanmar, expressed concern over the civilian deaths in Muse and called for swift aid deliveries to those affected.
"The UN encourages all parties to redouble their efforts to advance the Peace Process," he said in a statement.
Suu Kyi, the first civilian leader of the former junta-run country in decades, lacks control over security policy and the still-powerful military, which has retained key government posts in a delicate power-sharing arrangement.
On Saturday an anti-war protest in Yangon was broken up by riot police, who detained at least nine demonstrators.
Rights groups condemned the heavy-handed response.
"It is outrageous that the local government and police chose to confront peaceful anti-war protesters with riot shields, violence and arrests," said David Baulk, a Myanmar specialist with Fortify Rights.