More than 100,000 migrants have passed through Serbia this year, mainly from countries such as Syria, Iraq and Afghanistan, to seek sanctuary in the wealthy countries of Europe. <br></br>A ray of light falls on a migrant in a warehouse in Belgrade, Serbia, Nov. 11, 2016. Marko Djurica/Reuters

A thousand migrants have occupied a derelict warehouse in the capital of Belgrade. A migrant wrapped in a blanket sleeps on the floor. Marko Djurica/Reuters

Border closures have left many stranded. Migrants cook onions inside a warehouse. Marko Djurica/Reuters

According to the U.N. refugee agency, around 6,400 migrants are currently registered in Serbia, while local non-governmental organizations say their number is close to 10,000. Rays of light shine through holes on walls of a warehouse. Marko Djurica/Reuters

Most of the migrants registered in Serbia arrive from Bulgaria and Macedonia. Migrants walk outside a warehouse at night. Marko Djurica/Reuters

A migrant sleeps on a piece of cardboard placed on the floor. Marko Djurica/Reuters

With the temperature near zero, migrants warm themselves and prepare food by the fire. Marko Djurica/Reuters

Wrapped in blankets, migrants rest on the concrete floor. There are no toilets around. Marko Djurica/Reuters

Serbian government and humanitarian agencies offer the migrants accommodation in refugee centers with heating and food - but despite the misery of their situation, they do not want to go. A migrant warms himself by the fire. Marko Djurica/Reuters

Doing so would formalize their situation and with neighboring European Union state Hungary letting in only between 10 and 30 migrants a day, migrants might have to wait up to nine months to exit Serbia legally. Migrants wrapped in blankets sleep on the floor. Marko Djurica/Reuters

Migrants brush their teeth outside the warehouse. Marko Djurica/Reuters

A migrant shaves his friend outside the warehouse. Marko Djurica/Reuters