HELSINKI, Finland -- Finns on Monday marked the 70th anniversary of the Winter War, a conflict that saw this tiny country hold off Stalin's Red Army for 105 days and suffer one-third as many casualties in weather that was so cold some soldiers hallucinated.

Finland lost the war, but its resistance against the massive Soviet war machine with its white-clad "ghost army" stunned Moscow, which had planned to occupy its western neighbor within a few weeks, into accepting peace.

Some 27,000 Finnish soldiers were killed and 43,000 wounded in a population of 3.7 million. The Soviet Union put its losses at 217,500 dead or wounded.

Many froze as temperatures dipped to as low as minus 49 degrees Fahrenheit (-45 C) during the three months of hostilities — one of the coldest wars in history. The extreme weather caused frostbite and hallucinations that forced a drop in guard duty from two hours to 30 minutes.

Viljo Kontio, 95, served in a signals battalion near the border when Soviet troops invaded.

"Grenades rained on us and the Russians came straight at us in open areas. In the thick forest, the Soviet boys didn't dare fight because they feared the snow-camouflaged Finns," Kontio said. "I saw with my own eyes how the Russians motivated their fighters differently to us — withdrawing soldiers were coldly shot."

The Soviet losses and unsuccessful campaign forced Stalin to reassess his plans and agree to a truce, leading to a peace treaty signed by Finland and the Soviet Union on March 12, 1940.

The question of who began the war had been contentious until the breakup of the Soviet Union when Russian historians admitted Stalin was to blame.

On Nov. 26, 1939, Soviet Foreign Minister V.M. Molotov accused Finnish troops of firing at the Russians across the 800-mile (1,300-kilometer) border near the village of Mainila, in southeastern Finland.

The Finns have consistently denied firing the "Mainila Shots," and Russian historians now acknowledge that the Red Army fired the shots and Stalin used the alleged incident as a pretext to invade Finland four days later.

Though the Russians were well equipped, many historians considered their strategy and planning as poor. But after three months of holding off Soviet forces, which at the outset numbered 450,000, the Finns began to tire due to a lack of adequate backup and ammunition.

Field Marshal C. G. Mannerheim, the commander of the Finnish troops, rejected an offer of assistance from the Western powers, saying it was "too little, too late," and recommended that Finland negotiate peace after a Soviet offensive in March 1940.

The peace treaty forced Finland to cede 11 percent of its land, mostly large areas of eastern Karelia, and more than 400,000 Karelians were resettled in Finland.

Monday's ceremonies included wreath laying at tombs and graveyards, exhibitions, special events in schools and a memorial service in Helsinki Cathedral attended by President Tarja Halonen.