SRINAGAR: Four Indian army officers and two porters were killed on Monday in an avalanche on the Siachen Glacier, a defense spokesman said on Monday. The incident, in which eight other people were trapped, occurred at an altitude of 19,000 feet on the glacier. “The cause of death is extreme hypothermia,” the spokesperson said, adding that two of the eight people had been rescued. The Siachen Glacier in the Karakorum range is known as the highest militarised zone in the world. Thousands of Indian and Pakistani troops contest an area at altitudes above 20,000 feet where they must deal with altitude sickness, high winds, frostbite and temperatures as low as minus 60 degrees Celsius.