The Karen National Union (KNU) claims 246 junta soldiers were killed and 239 injured over the past 11 months in its Tanintharyi Region territory.
From January to November 16, 123 clashes broke out in Dawei and Myeik districts, where its armed wings the Karen National Liberation Army, Karen National Defense Organizations and resistance allies operate.
Fourteen Karen resistance fighters were killed and seven injured in recent clashes, the KNU said on Saturday.
This month around 30 shootouts between regime troops and resistance groups erupted in Tanintharyi Region, killing 48 junta soldiers and injuring 26, the KNU claimed.
The KNU said its forces suffered two deaths and four injuries.
The country’s oldest rebel group has been fighting the regime since March last year after hundreds of peaceful, anti-regime demonstrators were killed across the country.
The rebel group has trained several thousand resistance fighters from across Myanmar.
Resistance groups trained and armed by the organization are fighting in KNU territory in Karen and Mon states and Bago and Tanintharyi regions and beyond, including in Yangon.
By October an estimated 6,947 clashes had been reported with regime forces in KNU territory in which it said around 5,854 junta soldiers and allied border guard militia members were killed and 4,748 injured since the coup last year.