 In combat , the biggest cause of confusion among Finnish soldiers were Soviet tanks . The Finns had few anti @-@ tank weapons and insufficient training in modern anti @-@ tank tactics . However , the favoured Soviet armoured tactic was a simple frontal charge , the weaknesses of which could be exploited . The Finns learned that at close range , tanks could be dealt with in many ways ; for example , logs and crowbars jammed into the bogie wheels would often immobilise a tank . Soon , Finns fielded a better ad hoc weapon , the Molotov cocktail . It was a glass bottle filled with flammable liquids , with a simple hand @-@ lit fuse . Molotov cocktails were eventually mass @-@ produced by the Finnish Alko corporation and bundled with matches with which to light them . Eighty Soviet tanks were destroyed in the border @-@ zone fighting . 
