Police backed by armoured vehicles also spread coils of razor wire over rail tracks used by migrants to cross on foot from Greece to Macedonia. Macedonia shut the border to crossings on Thursday.
The United Nations voiced concern at the force used by the Macedonian riot police to disperse refugees and urged the Skopje government to establish “orderly management” of its borders.
The refugees see both Macedonia and Serbia only as transit routes to Western Europe, which is why Macedonia earlier relaxed controls on migrants, allowing them 72 hours to cross the country unhindered.