A German border policewoman looks after two children of a Syrian family after they arrived on a train from Budapest's Keleti station at the railway station of the airport in Frankfurt, Germany, early morning Sept6, 2015.[Photo/Agencies]

"REFUGEES WELCOME"

Wrapped in blankets and sleeping bags, long lines of weary people, many carrying small, sleeping children, got off buses on the Hungarian side of the border and walked through the rain into Austria, receiving fruit and water from aid workers. Waiting Austrians held signs that read "Refugees welcome".

"We're happy. We'll go to Germany," said a Syrian man who gave his name as Mohammed; Europe's biggest and most affluent economy was the favoured destination of most.

Austria said 9,000 people had crossed from Hungary on Saturday. The Austrian state railway company OeBB estimated it would have transported 7,500 migrants before stopping services for the night, with the last train from the border due to arrive in Vienna at 2100 GMT.

At the frontier with Hungary, Austrian police said the flow of people had slowed, with some still crossing on foot.

Hungary insisted the bus rides were a one-off as hundreds more people gathered in Budapest, in what has become Europe's most acute refugee crisis since the Yugoslav wars of the 1990s.

Almost emptied of migrants the night before, the main Budapest railway station was filling up again, a seemingly unrelenting human surge northwards through the Balkan peninsula from Turkey and Greece.

With trains to western Europe cancelled, hundreds set off by foot for the Austrian border, 170 km (110 miles) away, as others had tried to do on Friday. The Hungarian authorities allowed some to board trains taking them to, but not over, the Austrian border.