At least 20 Indian soldiers have been killed in a violent face-off with Chinese forces on the disputed Himalayan border, the Indian army said late Tuesday, the deadliest clash between the nuclear-armed neighbours in decades.

India had earlier said three of its troops were killed, but in a statement later Tuesday the army added that 17 more “who were critically injured (on Monday) in the line of duty at the stand-off location and exposed to sub-zero temperatures in the high altitude terrain have succumbed to their injuries, taking the total that were killed in action to 20”.