Macedonian police tossed teargas cannisters at migrants trying to cross the Greek border on Wednesday, Greek TV footage showed, as Europe approved more assistance to Athens to relieve the dire conditions of those stuck in Greece.
The migrants at the Greek border town of Idomeni withdrew after the clashes and the situation calmed, the reports showed.
Around 300 migrants and two dozen police officers were injured in a similar incident on Sunday, when around 3,000 people attempted to force their way into Macedonia after being stuck for more than a month at the overcrowded camp.
The path to wealthy EU countries in the north was blocked last month when Macedonia declared its borders closed to all travellers without valid passports and visas, matching similar measures from Serbia, Croatia and Slovenia.
Last year, around 1 million people - mostly refugees from Syria and Iraq - applied for asylum in Europe, with Greece, Macedonia, Serbia, Hungary, Croatia and Slovenia having served as main transit countries.
The closures have lead to bottlenecks in Greece as migrants continue to cross the Aegean Sea from Turkey, but the European Union has brokered a deal with Ankara in a bid to reduce irregular migration to the bloc.
The European Commission has also tried to take pressure off Greece by awarding it emergency aid and redistributing some of its asylum seekers to other member states. But the programme has had limited success, with only 615 relocated out of the country so far.
On Wednesday the European Parliament cleared the way for another 100 million euros (113 million dollars) in refugee aid to be released through a new instrument for countries worst-affected by Europe's migration crisis. Much of it is expected to go to Greece.
The funds can be used to provide food assistance, emergency healthcare, shelter, water, sanitation and hygiene, protection and education, the parliament said.
The aid was allocated amid sharp criticism from human rights group over the humanitarian situation in Greece.
Pope Francis, a vocal champion of migrants, plans to assess the conditions himself on the Greek island of Lesbos on Saturday.
"Next Saturday I will go to the island of Lesbos, where over the past months many refugees have transited," the pope said during his weekly audience in St Peter's Square.
The purpose of his trip, he said, was "to express closeness and solidarity towards both the refugees and the citizens of Lesbos and all the Greek people which have been so generous in welcoming [migrants]."