In a derelict warehouse behind Belgrade's main coach station, up to 1000 migrants are trying to survive the freezing Serbian winter in a crumbling building with broken windows, no heating, or warm water. It is -10 Celsius and a bitterly cold blizzard is lashing them while they try to warm up by burning wood outside the grim warehouse they now call home. Some of the migrants, who mainly come from Afghanistan, are wrapped in blankets given out by agencies, but most shiver in jackets inadequate for the sub-zero temperatures they endure day and night. Some say it gets so cold at night that no matter how hungry and exhausted they are, they can't sleep. The ground outside the warehouse is frozen and slippery, and inside there is garbage on the floor. The youngest migrant was 12 and alone, without gloves or a scarf to help shield him from the constant cold. These terrible conditions are a stone's throw from the bustling cafes, restaurants and busy office buildings of a Serbian capital city.