The army in Myanmar's second city, Mandalay, has clashed with a local militia opposed to February's military coup.
The clashes are the first time the People's Defense Forces (PDF) have come up against the army in a major city.
The defence force is a collective name for militia groups that have sprung up in Myanmar since the coup.
Myanmar's military junta has violently put down anti-coup protests in the country, killing hundreds of civilians.
Until now, actions by the PDF have been limited to fighting in rural areas or small towns. Tuesday's clashes brought the violence to a major city, marking a new phase in the fallout from the coup.
According to local reports, troops raided a boarding school being used as a base by the militia, leading to an exchange of gunfire.