An Army helicopter, with two pilots and two soldiers, on Thursday went missing while flying over north Sikkim, triggering concerns over the fate of the machine and the personnel.
The Advance Light Helicopter (ALH) Dhruv helicopter of the Army Aviation Corps had taken off from Sewak Road Base in Siliguri at 10.30 am, Army sources said.
It lost radio contact at around 11.30 am, the sources said adding efforts are on to locate it.
The Base is under the 33 Corps headquarters based in Siliguri.
Dhruv is an indigenously-developed helicopter inducted in the Army only recently.