IDOMENI, Greece — Macedonian police fired stun grenades Friday to disperse thousands of migrants stuck in a no man's land with Greece and clashed with them as they desperately tried to rush over the border, a day after Macedonia's government declared a state of emergency on the frontier to halt a human tide heading north to the European Union.
About 3,000 migrants who spent the night in the open made several attempts to charge the police — and some hurled stones at the Macedonian forces. At least eight people were injured in the melee, according to Greek police.
Machine-gun toting police backed by armored vehicles spread coils of razor wire over rail tracks used by migrants to cross on foot from Greece to Macedonia. On Thursday, Macedonia shut the border to crossings.
Hours after Friday's clashes, however, Macedonian police started letting small groups of families with children cross the border by walking along railway tracks to a station in the Macedonian town of Gevgelija, where most take trains to the border with Serbia.
"They are letting groups of about 30-40 people go, probably because they want to control the rush into Macedonia," said a Syrian who gave only his first name, Hassan. He was walking with his family and children over a rusty bridge toward Gevgelija. "I think they'll let all of us go eventually."
Dozens of people fainted as they tried to position themselves in the line to cross, with riot police pushing them back with shields against the tide. Children cried and women wept in the chaotic scenes that left many migrants stranded for another night on the dusty field.
Among the injured was a youngster who was bleeding from what appeared to be shrapnel from the stun grenades that were fired directly into the crowd. A man holding a baby got tangled in razor wire separating the two sides.
The migrants, many with babies and young children, spent the chilly and windy night in a dusty field on the border without food and with little water. Some ate corn they picked from nearby fields.
"I don't know why are they doing this to us," said Mohammad Wahid, an Iraqi. "I don't have passport or identity documents. I cannot return and have nowhere to go. I will stay here till the end."
Aurelie Ponthieu, a Doctors Without Borders adviser, said in a statement that Macedonian authorities used violence against harmless and vulnerable people.
"The shocking scenes today are a result of extreme measures to prevent desperate people fleeing violence and war from crossing borders," the statement said. "But closing borders and using violence is not a solution, it is just provoking a humanitarian crisis on the other side."
The U.N. refugee agency, UNHCR, said in a statement that it is "particularly worried about the thousands of vulnerable refugees and migrants, especially women and children, now massed on the Greek side of the border amid deteriorating conditions."
Greece has seen an unprecedented wave of migrants this year, most fleeing wars in Syria and Afghanistan. More than 160,000 have arrived so far, mostly crossing in inflatable dinghies from the nearby Turkish coast — an influx that has overwhelmed Greek authorities and the country's small Aegean islands.
Few, if any, of the migrants want to remain in Greece, which is in the grip of a financial crisis. Most head straight to the country's northern border with Macedonia, where they cram onto trains and head north through Serbia and Hungary on their way to the more prosperous EU countries such as Germany and the Netherlands.
Last week, there were chaotic scenes at the Gevgelija train station involving hundreds of migrants trying to board the trains.
Macedonian police said blocking the refugees on the 50-kilometer (30-mile) frontier was introduced "for the security of citizens who live in the border areas and for better treatment of the migrants."
Police denied reports they fired tear gas to control the crowd on the border, saying shock grenades were used to prevent the migrants from the forced entry.
The army was deployed Friday to the border areas.
Until now, the border has been porous, with only a few patrols on each side. Sealing it disrupts the Balkan corridor for migrants who start in Turkey, take boats to Greece or walk to Bulgaria, then make their way through Macedonia or Serbia before heading farther north. Hungary has begun building a razor-wire fence to keep them out.
Almost 39,000 migrants, most of them Syrians, have registered as passing through Macedonia in the past month, double the number from the month before.
On Greece's eastern islands, hundreds of migrants arrive each day in overladen, often unseaworthy boats. The Greek coast guard said Friday that a patrol boat from Europe's border agency Frontex had spotted a capsized boat off the island of Lesbos. One migrant was found dead and 15 others were rescued.
Separately, the coast guard said it had picked up 620 people in 15 search-and-rescue operations in the last 24 hours off Lesbos, Samos, Agathonissi, Leros, Farmakonissi, Kos and Megisti. That doesn't include hundreds more who have reached the islands on their own.
A Greek government-chartered ferry carrying about 2,200 mainly Syrian refugees from Lesbos — which sees the highest number of arrivals in Greece — reached Athens later Friday.
One of the Syrian passengers, Alan Jamil, said he was not aware Macedonia had closed its border but would find a way out of Greece.
"We don't know, but it isn't difficult for us because we will cross the border, we will ask our relatives how they go, and we will pass," he said.
Thousands of refugees waiting to head for Athens and then the border with Macedonia are stuck on Lesbos, because it is difficult to find ferry tickets at the height of the summer holiday season.
Before heading for Lesbos, the Eleftherios Venizelos ferry had been used as a floating refugee registration center on Kos, an island near the Turkish coast where hundreds arrive daily in small boats.
Associated Press writers Costas Kantouris in Thassos and Elena Becatoros and Nicholas Paphitis in Athens contributed.