As a clandestine army operating in an enemy-occupied country, and separated by over a thousand kilometers from any friendly territory, the Home Army faced unique challenges in acquiring arms and equipment, though it was able to overcome these difficulties to some extent and to field tens of thousands of armed soldiers. Nevertheless, the difficult conditions meant that only infantry forces armed with light weapons could be fielded. Any use of artillery, armor or aircraft was impossible (except for a few instances during the Warsaw Uprising, such as the "Kubuś" armored car). Even these light-infantry units were as a rule armed with a mixture of weapons of various types, usually in quantities sufficient to arm only a fraction of a unit's soldiers.