Since the summer, hundreds of thousands of refugees and migrants have crossed into Austria, the last country on the so-called Balkan route to Germany, the chosen destination for most of the migrants. Many are transported through Austria straight to the German border.
In spot checks in the southern province of Carinthia, police and translators said they had noticed a rise in the number of unregistered people whose language skills did not match their purported nationality. 65 people were sent back to Slovenia on Wednesday, and around 100 over the weekend.
The spokesman for the police in Carinthia declined to say where the migrants who were sent back to Slovenia were from.
The flow of refugees and migrants into Austria from Slovenia has shifted to Carinthia after a fence was put in place at the main crossing between the two countries, further east in the province of Styria.
In Upper Austria, Greens MP Rudi Anschober has complained that German authorities are currently sending between 50 and 100 migrants back to Austria every day, on the grounds that they have no intention of applying for asylum in Germany and want to travel to Sweden to join relatives there.
Anschober complained that Upper Austria has had to find accommodation for an extra 2,000 people this month, who do not want to stay in Austria.
More than a million people have made the perilous journey across the Mediterranean to Europe this year, according to the UN refugee agency. The majority (50 percent) are from Syria, and 21 percent are from Afghanistan. At least 3,735 people are believed to have died trying to reach Europe.