They were among at least 80 regime forces killed in Chin, Kachin and Karen states and Sagaing and Magwe regions, resistance groups said.
In need of financial support, PDF groups are increasingly going public with their rudimentary weapons-production efforts.
Regime troops are increasingly using mines to terrorize civilians in the strategically important state.
The Kalay PDF, KNDF, Karen Army and CNDF reportedly inflicted heavy casualties on junta forces in firefights and mine ambushes on Monday.
PDF groups and ethnic armies fought with and ambushed junta troops and pro-regime militias in six states and regions.
Civilian resistance fighters attacked junta troops and police in ambushes and raids in Sagaing, Magwe and Kayah; atrocities against unarmed villagers reported in Kayah.