BELGRADE (Reuters) – Several hundred refugees set off from central Belgrade on Tuesday morning and headed for the Hungarian border, holding handwritten banners and chanting demands for open borders, Reuters witnesses said.

The crowd walked north along the city’s Sava river, stopping occasionally to negotiate with police. All of them appeared to be men and boys about 15 or older. “We are people, not animals,” read one banner.

Some 7,000 migrants, most fleeing war and poverty in Syria, Iraq and Afghanistan and elsewhere, are trapped in Serbia, prevented from continuing further into Europe by fences now running the length of the Hungarian-Serbian border.

“We will walk to border with Hungary,” said Sadaqat Khan, a Pakistani in his 20s from Qetta. Most of the migrants seek sanctuary in the wealthy countries of Northern Europe. “We do not want Serbia,” Khan said.

Many migrants in Belgrade, most of whom bed down in makeshift camps by the city’s central rail station, had thought Hungary’s referendum last weekend on migrant quotas meant the border would be opened.

In fact, Hungary voted on whether to accept European Union quotas for taking in refugees, and almost all of those who went to the polls voted against the quotas. However, less than half the electorate voted, rendering the results of the referendum invalid.

A large group of refugees who left Belgrade’s camps earlier this year got as far as the northern city of Novi Sad, but from there they were taken to reception centers on the Serbian side of the border.

(Reporting By Aleksandar Vasovic, Fedja Grulovic and Branko Filipovic; Writing by Thomas Escritt; Editing by Larry King)