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 ?RF, she urged the closure of what she called the "Eastern Balkans migrant route".

Her words are a reference to the "Western Balkans migrant route", a concept that was used to describe the movement of migrants from the Middle East, who have been crossing into Europe from Turkey, through Greece, Macedonia, Serbia, Croatia and Slovenia to Austrian and from there to Germany.

Leitner, however, opined there were risks that, after the latter rote was practically closed following an agreement between the EU and Turkey, leaving tens of thousands stranded on the Greece-Macedonia border, Bulgaria might turn into a more popular transit destination.

The Eastern European country has not been in the way of migrants since 2013 (when it became, alongside Greece, one of the first European states to see a rise in migratory pressure). It has been avoided partly due to stepped up security measures at the border and partly because of reiterated reports of violence, abuse and pushbacks of migrants on behalf of police officers.

However, other reports have suggested that offers placed by smugglers to enter Greece by taking a perious Aegean Sea journey from the Turkish coast are cheaper compared to a journey through Bulgaria.

Leitner is quoted by Austrian daily Die Presse as saying that the EU-Turkey deal "does not solve the problem".

She cited a recent announcement of Austrian authorities that intensified smugglers' activity had been noted in direction to Bulgaria.

Leitner visited Bulgaria earlier in March, alongside Austrian Defense Minister Hans-Peter Doskozil.

Sofia had insisted itself that a deal with Turkey should include a prerequisite of tightened security measures along its border with Turkey and guarantees that a new migrant route would not be allowed to emerge.

The final agreement reached last week, however, did not touch the issue.