Macedonia has defended its handling of security at the country's border with Greece, where migrants were beaten back with truncheons and riot shields.
The government had to act because up to 3,500 were entering each day, but migrants had not been mistreated, said Foreign Minister Nikola Poposki.
The migrants, many from the Middle East, want to reach northern EU states.
Amnesty International said they had been treated more like rioters rather than refugees.
Macedonia has declared a state of emergency to cope with the situation.
Hundreds of migrants advanced on the border's security forces on Friday.
Mr Poposki told the BBC he had not seen pictures of people being beaten back but there had been an "intervention" after the situation had "dramatically deteriorated".
He said: "In the last several days there has been a dramatic increase of inflow of migrants and we have reached numbers of 3,000 to 3,500 per day which obviously is not something a country of two million people and our resources can handle on a daily basis.
"We had to reinforce the control of illegal entry of Macedonian territory."
Medecins Sans Frontieres said it had treated 10 people with wounds from stun grenades fired by Macedonian troops near the Greek border village of Edomeni.
Amnesty International deputy Europe director Gauri van Gulik said the authorities had responded "as if they were dealing with rioters rather than refugees who have fled conflict and persecution".
Responding to criticism, Mr Poposki said: "Macedonia's definitely not a place where they [migrants and refugees] have been mistreated.
"For a country of two million people with no resources, not a member state of the European Union - meaning not being able to apply for all the funds that are available - we have handled this crisis in a pretty decent manner."
A man at the border who had fled the conflict in Syria, paying a smuggler for passage from Turkey to Greece told the BBC: "Nobody knows what's the idea of closing the border."
He explained he did not want to stay in Greece because of its financial crisis.
He said: "I am looking for a normal life of peace and democracy. We can't go back. We have to go ahead.
"My dream is to have a university to study in."
He added that travelling through Bulgaria was not an alternative as it was too dangerous.
Mr Poposki said all migrants had to register on entering Macedonia, and they had 72 hours to decide whether they would apply for asylum or pursue their route north.
The BBC's James Reynolds says he understands that Macedonian security forces plan to let several hundred migrants in at a time on Saturday to coincide with train departures north towards Serbia and the rest of Europe.
Meanwhile, the UN refugee agency, the UNHCR, has expressed concern for "thousands of vulnerable refugees and migrants, especially women and children, now massed on the Greek side of the border amid deteriorating conditions".
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It urged Macedonia to "establish an orderly and protection-sensitive management of its borders" while appealing to Greece to "enhance registration and reception arrangements" on its side of the border.
The UNHCR also said it had been assured by Macedonia the border "will not be closed in the future", but did not elaborate.
In recent weeks there have been chaotic scenes at Gevgelija station, with migrants trying to clamber on board packed trains heading north.
Greece itself has seen almost 160,000 people landing on its shores since January, the UN estimates, with 50,000 arriving in the past month alone.
The migrants trying to reach northern and western Europe come from the Middle East, Africa and Asia. Many arriving in Macedonia are escaping the conflict in Syria.