Athens: Some 700 refugees and migrants were being held in Macedonia on Tuesday after they managed to slip across the border from Greece, a frontier that has been shut for a week.
Dozens of others who failed to cross were returning to the overflowing Idomeni camp on the Greek side, where some 14,000 people are stuck in increasing squalor following a string of border closures on the European migrant route.
European Migration Commissioner Dimitris Avramopoulos was set to visit the camp at Idomeni at around midday on Tuesday.
Giorgos Kyritsis, spokesman for Greece`s migration coordination agency, said the hundreds who managed to cross the border Monday were still in Macedonia after they were intercepted by the Macedonian army.
"If the authorities ask us to take them back, we will examine the request," Kyritsis told public broadcaster ERT.
A group of around 80 journalists and activists who were detained by Macedonian police after travelling with the group, including an AFP video journalist, were released and allowed to return to Greece, Kyritsis added.
A local Greek police source said Macedonian authorities had pushed back groups of migrants from unguarded parts of the border during the night.
ERT reported that dozens who were blocked from entering Macedonia from the Greek side of a river were heading back to Idomeni after tramping through the night in the cold and rain, carrying children and babies.
Greek authorities said the migrants who tried to breach the border on Monday -- around 1,500 in total, according to media -- had read leaflets in Arabic describing the route across the river.
The document warned migrants that they risk being sent back to Turkey if they stay in Greece, the ANA news agency reported.
Dozens of Greek police had tried to block the route, before giving up because of the size of the crowd.
