Police used tear gas and batons against demonstrators who protested Sunday against planned strict controls at the border between Austria and Italy, Austrian press agency APA reported.
Austria deployed some 300 officers at the Brenner, a mountain pass that divides the two countries, while some 250 mostly Italian demonstrators staged their protest against Vienna's plans, a police spokesman told dpa earlier.
The Austrian government is preparing to set up checkpoints and fences at the Brenner.
It has warned Rome that it will start strict border checks if the migration route shifts to Italy and Italian authorities are unable to stop people from traveling on to Austria.
At a similar demonstration at the Brenner in early April, 15 demonstrators and 15 police officers had to be treated after tear gas was used.
Vienna's plan has raised alarm in Italy because it may hinder traffic at the mountain pass, which straddles one of Europe's most important road and rail cargo routes.
In addition, the open Brenner border has carried a highly symbolic meaning in the region, as it links Austria's Tyrol province with Italy's German-speaking South Tyrol province.
Austria's new interior minister, Wolfgang Sobotka, said Saturday that he would seek dialogue with Rome on this matter, but at the same time he warned that "the fence will be put up if Italy takes no measures."