The groups warned if the military did not stop killing peaceful protesters, they 'will cooperate with all nationalities who are joining Myanmar's spring revolution in terms of self-defence'.
Insurgents from different ethnic groups have battled the central government for decades for greater autonomy. Though many groups have agreed to ceasefires, fighting has flared in recent days between the army and forces in the east and north.
Heavy clashes erupted on the weekend near the Thai border between the army and fighters from Myanmar's oldest ethnic minority force, the Karen National Union (KNU).
About 3000 villagers fled to Thailand when military jets bombed a KNU area after a KNU force overran an army outpost and killed 10 soldiers, an activist group and media said.
Thai authorities denied accounts by activist groups that more than 2000 refugees had been forced back, but a Thai official said it was government policy for the army to block them at the border and deny access to outside aid groups.
A temporary suspension of fighting; a truce.
A rebel or revolutionary.
Pinned down by grenade and machine-gun fire from an insurgent, the assault force was unable to move without taking casualties.
Talk about a dream, try to make it real.