The office of the country's leader, Aung San Suu Kyi, blamed the Myanmar National Democratic Alliance Army for today's attack, which it said killed five civilians and five police officers.
It said the bodies of 20 other people were found after the fighting in the town of Laukkai in northern Shan state. It was not clear if the 20 were among the estimated 50 attackers.
Gruesome photos of some of the dead and wounded were posted along with the statement on Suu Kyi's official Facebook page.
The fighting was the most dramatic recent violence in the area, where the government and rebels have been contending for territory. Similar fighting has been taking place further north in Kachin state involving other ethnic rebel groups. The rebels say they are countering attacks by the government.
Also Read
Fierce fighting between the government and the rebel group, which represents the Kokang, an ethnic Chinese minority, last occurred in 2015, sending tens of thousands of civilians fleeing across the border to China.
The Myanmar National Democratic Alliance Army is led by ethnic Chinese Peng Jiasheng, who once was chief of the officially sanctioned Kokang administrative zone but was ousted from power in 2009.
Disclaimer: No Business Standard Journalist was involved in creation of this content