A Thai rescue helicopter has crashed in Myanmar's northern Kachin state, authorities said.
The army and regional police were trying to access the crash site, reported Xinhua Tuesday.
The helicopter had gone missing Saturday.
The helicopter, an Advance Aviation B-4, which set out for the search and rescue operation of two missing Myanmar mountaineers earlier, lost contact with the ground on its way to the base camp, 20 minutes after it took off from the Putao airport Saturday.
One Thai pilot and two Myanmar pilots were onboard the helicopter.