Sources said, Singh, who is on a tour of Singapore, had called General Rawat on the telephone to know about the tragedy. Six persons, including four Army soldiers and two civilian porters, have been killed in Siachen Glacier after being hit by an avalanche on Monday afternoon.

On Tuesday, Singh tweeted, "Deeply pained by the demise of soldiers and porters due to avalanche in Siachen. I salute their courage and service to the nation. My heartfelt condolences to their families."

Army sources said work is underway to transport the dead bodies of the deceased soldiers to their hometowns.

According to the officials, eight personnel were trapped in an avalanche at around 3 p.m. on Monday and the Avalanche Rescue Teams from nearby posts were rushed to the location to pull them out.

The rescuers managed to extricate all the eight personnel from under the debris and seven critically injured persons, accompanied by medical teams providing critical care, were evacuated by helicopters to the nearest Military Hospital, where all life-saving resuscitative measures were instituted.

Despite best efforts, six persons - four soldiers and two civilian porters - succumbed to extreme hypothermia, officials said.