Police have stopped a group of ethnic Serbs from northern Kosovo from blocking a border crossing with Serbia.
The businessmen are protesting the introduction of new customs duties at checkpoints.
The EU-brokered deal is seen as a crucial step to improve relations between the two former enemies.
But the Serb business community in has refused to pay the new charges.
Around 40,000 ethnic-Serbs live in the north of Kosovo.
The area is often the centre of disputes over Belgrade’s ongoing rejection of Kosovo’s independence, which is recognised by 96 countries.