A group of migrants who had marched for two days from the Serbian capital have been stopped on the border with Croatia.
Around 150 migrants, mainly from Afghanistan and Pakistan, left Belgrade to walk the 125 kilometres to the Croatian border.
They are demanding free and secure passage to Western Europe.
The majority who arrived at the Serbian border town of Sid said they would not wait until the frontier with Croatia was opened.
They reportedly refused accommodation in a nearby reception centre.
A number are stranded on the Serbian side of the Tovarnik crossing.
Was there any trouble?
A group of migrants scuffled with police.
Around 100 broke a Serbian police cordon and tried to enter Croatia across fields.
They were stopped by police from both countries who encircled them.
What has Croatia said?
The country’s interior minister says migrants will not be allowed illegal entry.
What has Serbia said?
Serbia’s Interior Minister Nebojska Stefanovic says his country will not allow migrants to block highways and border crossings to “cross into another country which would not take them.”
Is this the first march of its kind?
Last month, another group tried a similar march toward the Hungarian border, but eventually decided to return to Belgrade.
Hungary, another EU member, has practically sealed its borders to migrants.
How many migrants are currently registered in Serbia?
Around 6,400, according to the UNHCR.
They are from countries like Syria, Iraq, Pakistan and Afghanistan.
Local NGOs, however, think the number is closer to 10,000, with many arriving from Bulgaria and Macedonia.
Last year, a total of 579,518 migrants and asylum seekers were registered arriving in Serbia, out of the more than one million who made it to Turkey by land and sea.
What they are saying
“There is not a single reason why anyone should enter Croatia illegally. Croatian police will protect the border from such attempts,” – Croatia’s Interior Minister, Viaho Orepic