Austrian border barrier

The fence will be extended initially by 80 kilometers and will eventually protect the full length of the river borders with Turkey

If Austria and Slovenia seal their borders to migrants, Bosnia and Herzegovina will be forced  to close its own borders with Serbia and Montenegro, Slobodan Ujic, Director of the Foreigners' Service of Bosnia, warned on Tuesday.

Austria will be able to declare a state of emergency, if migrant arrivals suddenly rise, and reject most asylum-seekers directly at the border under a new bill adopted on Wednesday, newswires reported.

The hotly-disputed legislation is "one of Europe's toughest asylum laws", according to AFP.

Austria has re-introduced checks on its border with Hungary to curb the flow of irregular migrants, AP reported on Monday.

Austrian police have said that the number of attempts to smuggle illegal migrants into the country has increased since the Western Balkan migration route was closed to migrants earlier this year.

Austria plans to further restrict its regulations for granting asylum by setting additional limits on who qualifies for safe haven, the AP reported on Wednesday.

The new restrictions, to take effect from the middle of May 2016, have been unveiled by Interior Minister Johanna Mikl-Leitner.

Austria is ready to support Bulgaria'sefforts to improve border security in view of potential increase in migration pressure, including by secondment of police officers, a senior Austrian official has said.

A new corridor might be opened up through Bulgaria for migrants heading to Western Europe, Austrian Interior Minister Johanna Mikl-Leitner warned on Sunday.

In an interview with public broadcaster ÖRF, she urged the closure of what she called the "Eastern Balkans migrant route".

Bulgarian Prime Minister Boyko Borisov pressed on March 12 to have his country's borders protected as part of a proposed EU-Turkey deal aimed to stop the flow of migrants to Europe.

Bulgarian Prime Minister Boyko Borisov said the country should be able to count on support from the EU in border protecton just as any other "frontine state".

The Balkan migrant route will remain permanently closed, Austrian Interior Minister Johanna Mikl-Leitner has said.

Only such a "consistent signal" will deter migrants from crossing the Mediterranean from Turkey to reach Europe, she added.