Trapped in Serbia, Migrants Shelter in Warehouse The warehouse "is for dogs, not for people," said a migrant who came from Kabul.

 -- When Taliban insurgents knocked on his house door in Jalalabad around six months ago and asked him to join their forces, Darvish, 15, borrowed money from his uncle and left Afghanistan.

"My father had worked as a driver for a U.S. company and he was killed by Taliban forces three years ago. When they came to recruit me, my mother told me to leave the country," he said.

Darvish arrived in Serbia in early November having crossed through Pakistan, Iran, Turkey and Bulgaria, and is now among 1,000 migrants who have occupied a derelict warehouse in the capital Belgrade.

"Together with friends I met on the road I am trying to reach Italy," he told Reuters. He wants to save enough to pay for his mother's trip to Western Europe.

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. But border closures have left many stranded.

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. They mostly arrive from Bulgaria and Macedonia.

In the rundown warehouse along the Sava River bank, a few hundred meters away from prime real estate in Belgrade, Darvish and his friends lit pieces of wood they collected to warm up with the temperature near zero.

They sleep on red blankets laid on the concrete floor and there are no toilets around.

The 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.

Doing so would formalize their situation, and with neighboring European Union state Hungary letting in only between 10 and 30 migrants a day, Darvish's group might have to wait up to nine months to exit Serbia legally.

Or they might face deportation if they fail to meet asylum criteria.

"This [the warehouse] is for dogs, not for people," Said, who came from Kabul, said. He has been living in the warehouse for a month, but does not want to go to a warmer room in one of 11 refugee centers in Serbia.

Earlier in November, a group of migrants began marching from the warehouse to the border with Croatia, but after a two-day walk, they were turned back by the border police.