Clashes between Myanmar troops and ethnic Kokang rebels near the Chinese border have left 47 government soldiers dead and 73 wounded, state media said.
The Global New Light newapaper of Myanmar said on Friday that there have been more than 13 clashes in the past several days between government troops and Kokang rebels near Laukkai close to the border, with the government carrying out five airstrikes.
The number of rebel casualties was not immediately known.
Kokang fighters with "heavy weapons including anti-aircraft machine guns" attempted to capture the Kokang region's capital Laukkai, just a few kilometres from the Chinese border, but were repelled by the army, Global New Light said.
It added that a 200-strong force of Kokang rebels attacked a military base in the Kongyan area on Thursday, shelling the headquarters.
"So far, the fighting has left government forces with 47 dead, 73 wounded and five vehicles destroyed," said the English language report.
The fighting, the report said, has been serious enough for the government to inform China, which is concerned about the clashes because they force civilians to flee across the border.
Renewed conflict in the Kokang area of Shan state, which had been largely dormant for nearly six years, represents fresh challenges for the government, which is trying to forge a comprehensive ceasefire deal with the country's myriad ethnic armed groups.
Independent analyst Richard Horsey said attacks by the Kokang rebels appeared "quite audacious", adding that fighting was likely to continue.
"Having suffered such significant losses, local commanders are not going to want to give up on this one," he told the AFP news agency.
Horsey said that the description of the rebels as "renegades" in state media reporting could be an effort by the government to draw a distinction between the Kokang fighters and the ethnic armed groups taking part in ceasefire negotiations.