First groups of refugees have started arriving in Croatia as they seek new entry points into the European Union after Hungary sealed off its border with Serbia.
About 80 people crossed into eastern Croatia after being taken by bus to the Serbian border town of Sid, following an all-night ride from the southern border with Macedonia.
Dozens of police and aid workers waited for the migrants across the border in Croatia, where they are being registered. Local media say some migrants have sought to cross into Croatia through nearby fields to avoid registration.
Officials say more buses are expected to arrive in Sid later.
Migrants have avoided Croatia in the past because they must still go into Hungary or Slovenia before reaching Austria or Germany.
Meanwhile, small groups of migrants are continuing to sneak into Hungary from Serbia, despite a move by Hungarian authorities to start arresting those trying to breach the new razor-wire barrier.
Police on horseback surrounded a group of 14 Afghans, including five young girls and an elderly woman, in a field close to the fence.
Small groups of young men also walked along roads leading away from the border. One asked a passing reporter: “Is this the way to Budapest?”
The evidence of crossings came a day after Hungarian police arrested at least 174 migrants for illegally breaching the border or damaging the fence.
Further west, Austria has started selective controls of vehicles at three main border crossings from Hungary as it tries to impose some order over the stream of migrants.
Police said the controls could be extended to 10 crossings, with vehicles being stopped selectively for checks of passports and other travel documents.
Interior minister Johanna Mikl-Leitner has said Syrians and others in danger in their home countries can continue to ask for asylum in Austria. She said they will also be free to travel on to Germany, as has been the case up to now.
The Greek coast guard says it has picked up hundreds of people from the sea near eastern Aegean islands as they attempted to reach Greece from the nearby Turkish coast. The coast guard said it rescued 773 people in 19 separate search and rescue operations from Tuesday morning to Wednesday morning off the coasts of the islands of Lesbos, Chios, Samos, Kos and Rhodes.
The figures do not include the hundreds more who manage to reach the islands themselves, usually in overcrowded inflatable dinghies or wooden boats.
More than 250,000 people have reached Greece so far this year, the vast majority of them Syrians or Afghans fleeing conflict at home.
Few, if any, want to remain in financially strapped Greece, with most heading north overland through the Balkans to more prosperous European countries such as Germany and Sweden.
Hungary's foreign minister says the razorwire fence on its border with Serbia is needed to secure the European Union's external border and will remain as long as large numbers of refugees keep trying to enter Hungary.
Minister Peter Szijjarto said that “only a physical obstacle” could help Hungary protect its border as long as refugees were able to pour into fellow EU member Greece and then make their way north.
He urged the EU to send forces to help Greece control the influx, to which Hungary would make a “massive contribution”.
Mr Szijjarto said those arriving from Serbia and applying for asylum in Hungary would be sent back to Serbia if their claims are rejected.