The Cheetah helicopter crashed in Tawang, around 16 kilometres (10 miles) south of the Line of Actual Control which divides India's northeastern Arunachal Pradesh state from Chinese territory.

Both officers were airlifted for treatment but one succumbed to his injuries on the way, an army statement said.

"The exact cause of the crash is being investigated," it added.

China and India fought a full-scale war in 1962 over control of Arunachal Pradesh, which Beijing claims in its entirety and considers part of Tibet.

Tensions have simmered between the countries since a clash elsewhere on their disputed Himalayan border in 2020 that left 20 Indian soldiers and at least four Chinese troops dead.

This is the second such accident involving a Cheetah helicopter this year.

A pilot was killed in March when his chopper went down in a remote area in the northern Kashmir region, local media reported.