A steady flow of migrants is continuing through the Balkans and Central Europe despite attempts to restrict them, as the EU struggles to weather the crisis.

More than 6,000 have reportedly so far entered Croatia from Serbia after Hungary closed its border on Tuesday.

Meanwhile 7,266 migrants arrived in Germany on Wednesday, twice the number for the previous day.

Many of the migrants are fleeing fighting in Syria, Iraq and Afghanistan and want to reach Germany.

Hundreds were involved in clashes at the Hungary-Serbia border on Wednesday, trying to breach a razor-wire fence.

Separately on Thursday, the European Parliament backed plans for the mandatory relocation of 120,000 refugees around the EU.

The move comes ahead of a meeting of interior ministers next Tuesday to discuss the measures, and correspondents say it will put pressure on the ministers to give their approval.

Croatian police said 5,650 migrants had crossed into the country since early Wednesday.

Many travelled by bus to the Croatian border after Hungary completed a fence along its border with Serbia. Others arrived on foot from the town of Horgos, scene of Wednesday's clashes during which Hungarian security forces used tear gas and water cannon to stop migrants forcing their way into Hungary.

Large numbers have crowded onto a small railway station in the Croatian border town of Tovarnik where a special train is taking them to the capital Zagreb.

Croatian Interior Minister Ranko Ostojic told Croatian TV on Wednesday that the police were currently in control of the situation but that if migrants continued to arrive in large numbers then the authorities would have to think about taking a different approach.

Health Minister Sinisa Varga said Croatia was expecting an estimated 20,000 migrants to arrive in the next two weeks.

Croatia said it would allow migrants to travel into northern Europe, but officials in Slovenia - which borders Croatia to the north - have said they would tighten their border security and would stick to rules which require asylum-seekers to register on arrival.

Slovenia, like Hungary, is an entry point to the borderless European Schengen zone, which normally allows people to travel between member countries without restrictions.

In other developments:

• Germany extends border controls currently in place with Austria to the Czech Republic
• Authorities in Paris, France, are evacuating more than 500 migrants from tent camps and sending them to special migrant housing centres, the Associated Press reports
• Bulgaria is sending extra troops to its border with Turkey in case of a further influx of refugees, its defence minister says
• Austrian railways say services to and from Hungary, suspended on 10 September, will resume on Thursday

'Human shields'

On Wednesday, there were chaotic scenes near Horgos, with fires burning and police vehicles and ambulances arriving on the Serbian side of the border, across from massed ranks of riot police on the other side.