Two migrants die in traffic accident in Serbia`s south - police
Serbia was a focal point for migrants last year, when hundreds of thousands fleeing wars and poverty in the Middle East and Asia traveled up through the Balkans to reach wealthy Western Europe.
Although that route was closed off in March, Serbian authorities estimate a further 110,000 migrants have passed through the country, many using smugglers to travel across Serbia and cross its barbed-wire border with Hungary.
On Monday, Serbian authorities arrested three men on suspicion of people trafficking after 77 migrants were found hidden in cargo vehicles.
According to the UN refugee agency, around 7,000 migrants are stranded in camps in Serbia.