Conflict has also intensified in the Sagaing and Magway regions, where locals this week accused the military of burning down homes and displacing thousands
Myanmar anti-junta dissidents have carried out a bomb attack on security forces near Yangon, with several killed in an ensuing firefight, the military and media said.
The Southeast Asian nation has been in turmoil since the military toppled Aung San Suu Kyi's elected government in February, sparking mass pro-democracy protests and a bloody crackdown by the military.
Various townships across Myanmar have formed so-called "people defence forces" to fight back against the junta, although the majority of clashes have been reported in rural areas.
Security forces were travelling through Khayan, a suburb of Myanmar's commercial hub Yangon on Friday when they were attacked with a homemade bomb, the junta said in a statement on Saturday.
"Both groups fired back and forth - a member of the security forces was injured," the statement said, adding that firearms and ammunition were confiscated after the clash.
"Some terrorists were... (killed), one of them was wounded."
Local media reported at least two dissidents were killed and one arrested.
Earlier this month a "National Unity Government" made up mostly of lawmakers affiliated with Suu Kyi's ousted party called for a "people's defensive war" and urged civilians to target junta assets.
Communications towers belonging to the military-owned Mytel company have been targeted across Myanmar.
Conflict has also intensified in the Sagaing and Magway regions, where locals this week accused the military of burning down homes and displacing thousands.
A 25-year-old woman from Magway's Gangaw township said: "The military has been crushing our region because of the local resistance forces," reports AFP.
"I lost some of my friends. I am heartbroken because I have witnessed all their atrocities with my own eyes."
Another Gangaw township resident said in one of its hardest-hit villages, Namg Kar, scores of homes have been razed since September 10 - a start-stop process over the past week as monsoon rains kept dousing the flames.
"They tried to burn down the whole village. But it was during the rainy season," said the resident, adding that Namg Kar's 4,000 residents have fled to a nearby jungle.
"They are afraid of the army as they could come back any time to the village," he said.
Images obtained by AFP showed Namg Kar villagers carrying buckets of water as smoke rose in the distance, while remains of burnt foundations smouldered.
The junta has not yet responded to a request for comment.