The Nazis seized from the French thousands of locomotives and rolling stock, stockpiles of weapons, and raw materials such as copper, tin, oil, and nickel.[109] Payments for occupation costs were levied upon France, Belgium, and Norway.[110] Barriers to trade led to hoarding, black markets, and uncertainty about the future.[111] Food supplies were precarious; production dropped in most of Europe.[112] Famine was experienced in many occupied countries.[112]