tatmadaw (army) personnel died in action and two civilians,” the report said, adding affiliated rebel groups, including the Ta’ang National Liberation Army and the powerful Kachin Independence Army, had also carried out attacks.
Rebels have said they are braced for a major army assault, after Myanmar imposed a state of emergency handing a local military commander sweeping powers.
An MP for Laukkai said his constituency was a virtual ghost town, with only a few residents left guarding their houses.
“People dare not to come back to the town,” said Kyaw Ni Naing, an ethnic Kokang MP for Laukkai told AFP from the capital Naypyidaw.
“We do not want to see any fighting. I want my region to be in peace as soon as possible,” he said, adding the refugees in China are desperate to return, but they “have to wait until the fighting stops”.
While the majority of the fleeing civilians have crossed into southwest China, tens of thousands more are believed to have been displaced on the Myanmar side of the border.
Several thousand have streamed into Lashio where they are seeking sanctuary in a cramped monastery.
Experts say Kokang area is viewed in Myanmar as a culturally distinct outpost, renowned for drug production and a cross-border trade with China.
Many of the ethnic Kokang are of Chinese origin.
China says it is providing relief to the refugees but has urged a swift end to the conflict.
Officials have blamed the Kokang rebel leader Phone Kya Shin for the sudden flaring of violence -- after six years of relative calm -- and called on Beijing to rein in any local officials who might be helping the group on its side of the border.
Myanmar’s President Thein Sein has vowed “not to lose an inch of Myanmar’s territory” to the rebels.
But the violence has undercut his well-trailed attempts to secure a nationwide ceasefire to end several festering insurgencies before breakthrough elections are held later this year.