The Advanced Light Helicopter (ALH) lost contact soon after its take off from Sagalee at around 3.50 pm before the rescue, Defence PRO Lt Col Sambit Ghosh said.
The chopper was evacuating people, stranded at Sagalee due to landslides, triggered by rains.
Sources at the Chief Minister's office in Itanagar said Chief Minister Pema Khandu was monitoring the situation.
The villagers have also asked to help the administration in locating the missing chopper, the sources said.
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