Three Indian soldiers were killed during a "violent face-off" with Chinese troops along the countries' de facto border in the Himalayas late Monday, the Indian army said in a statement.The incident occurred during a "deescalation process" underway in the Galwan Valley in the disputed Aksai Chin-Ladakh area, where a large troop build up has reportedly been taking place for weeks now on both sides of the border, before senior military commanders began talks earlier this month.