Macedonian police clashed with refugees on Saturday, while they were trying to pass from Greece to Macedonia. The police fired tear gas and stun grenades at refugees, after soldiers started building a fence along the border.
The incident took place after a refugee was electrocuted and suffered injuries by climbing on a train wagon on the border.
Alexandra Krause, an emergency coordinator at the UN Refugee Agency, said that the incident started after a group of refugees, believed to be Iranian, Moroccan and Bangladeshi, threw stones at the police.
"Several police officers were injured. We don't know yet how badly they're injured," she told Al Jazeera. "But as a reaction to this, police started using tear gas for a short while to disperse the crowd."
Macedonia has decided to close the border to most refugees, except Syrians, Iraqis and Afghans.
Human rights organisations have criticised Macedonia’s measures, saying that all refugees should be treated equally, despite their nationality.
Iranians, Pakistanis, Moroccans and other refugees have protested the country’s decision, while some Iranians have sewn their lips together, refusing to eat.
Earlier on Saturday, Macedonian authorities began building a fence, an act resembling Hungary’s way of keeping the refugees outside of the country and redirecting them to Croatia and Slovenia.
However, the Macedonian government said the border will not be closed completely.
Most of the refugees trying to reach Germany have landed in Greece, arriving by boat from Turkey, before starting their journey to get to the Balkan borders.