Church leaders in Tanai estimate that about a thousand people have sought sanctuary at churches in the town.
The move came after UNFC delegates refused to speak to journalists about the conference, and barred media from entering the meeting room.
Ceasefire groups urged Naypyidaw to facilitate “national-level political discussions” in Shan and Arakan states.
The seven militias say they have formed a committee to negotiate with the government, but will not discuss the NCA.
Locals say Mangpang Militia has threatened to murder residents and forced them to consent to a gold mining operation.
The move came soon after Union Day on 12 February when the NMSP held an armed parade despite objections from local Burmese authorities.