By BBC. Police have stopped members of the Pat Jasan Christian group – some wearing military-style uniforms – outside the town of Waingmaw.
Farmers says they will fight back if the campaigners are let through.
Myanmar is Southeast Asia’s top opium producer – and the world’s second largest after Afghanistan.
“Local army and police told us that they are still blocking the way for security reasons,” Hpala Lum Hkawng, a Pat Jasan member told French news agency AFP.