At least 20 Myanmar junta soldiers were reportedly killed and four others captured alive in a heavy clash with resistance forces in Demoso Township, Kayah State, on Saturday.
Regime forces attempted to re-occupy villages on the Demoso-Nanmekhon road which were seized by resistance groups in the last week of November.
Kone Thar, Thay Su Lal, Pu Phar, Daw Ka Mee and other villages had been seized by the regime forces over six months and they had to abandon the villages a few days ago due to the attacks from resistance forces.
On Saturday morning more than 100 troops attempted to raid Daw Ka Mee.
Troops based in Demoso shelled in support of ground forces and a fighter jet attacked resistance forces, said the KNDF.
During a daylong battle, resistance fighters reported seeing at least 20 dead junta soldiers. Four soldiers and weapons and ammunition were seized, a KNDF spokesman told The Irrawaddy on Monday.
The troops were from Infantry Battalion 108 that massacred 35 civilians, including women, children and two Save the Children staff, near Moso village in Hpruso Township, Kayah State, on December 24 last year.
The spokesman said the four detained soldiers are being treated and interrogated.
Three junta bases in Demoso continued to shell the area until Monday.
The KNDF asked people to avoid the road and urged displaced residents not to return to their homes as more clashes are expected.
In November an estimated 43 regime soldiers were killed and three others injured during around 28 clashes with resistance forces in Kayah State. Only two resistance fighters were killed, the KNDF reported.
Two civilians were killed and 34 injured and 57 civilian buildings were destroyed by junta shelling last month, the group said.