Frost covers the mask and part of the hat of a soldier of the People's Liberation Army (PLA) as he stand guard near the border of China and Russia in Heihe, Heilongjiang province December 10, 2014. REUTERS/Stringer

A soldier of the Marine Corps walks though smoke during a military drill on a snow-covered field at a military base in Taonan, Jilin province January 25, 2015. REUTERS/China Daily

Soldiers shout as they practice in Heihe, Heilongjiang province, December 16, 2014. REUTERS/China Daily

Soldiers throw snow onto their bodies during a winter training session at a military base in Heihe, Heilongjiang province, January 20, 2015. REUTERS/Stringer

Two soldiers of the Marine Corps take part in a military drill in Taonan, Jilin province January 27, 2015. REUTERS/China Daily

Soldiers take part in a drill during heavy snowfall in Heihe, Heilongjiang province, February 26, 2014. REUTERS/China Daily

Soldiers practice skiing in sub-zero temperatures in Heihe, Heilongjiang province, November 13, 2014. REUTERS/Stringer

A frontier soldier jumps through a ring of fire as part of training in Heihe, Heilongjiang province, March 5, 2014. REUTERS/China Daily

Soldiers of the Marine Corps eat breakfast during a military drill on a snow-covered field in Taonan, Jilin province January 25, 2015. REUTERS/China Daily

Soldiers practice shooting with pistols at a military base amid heavy snowfall in Hami, Xinjiang Uighur Autonomous Region May 23, 2014. REUTERS/China Daily

Soldiers of the Marine Corps clean their rifles inside a tent during a military drill at a military base in Taonan, Jilin province January 26, 2015. REUTERS/China Daily

Soldiers pour snow from tires onto their heads during a training session in Heihe, Heilongjiang province December 24, 2014. REUTERS/Stringer

Paramilitary policemen practice during their winter training against extreme weather, in Nanjing, Jiangsu province December 26, 2012. REUTERS/China Daily

Soldiers crawl on snow during a training session at a military base in Heihe, Heilongjiang province October 29, 2014. REUTERS/China Daily

Recruits take part in a training session at a military base in Jinan, Shandong Province, December 2, 2011. REUTERS/China Daily

Soldiers of the Marine Corps march during a military drill as the sun rises at a military base in Taonan, Jilin province January 28, 2015. REUTERS/China Daily