Hundreds of pro-refugee activists have turned up for a rally at the Brenner Pass crossing point to protest Austria’s plan to reinforce controls at its frontier with Italy. The peaceful march resulted in furious clashes with police, who arrested some 50 people.

At least five officers were injured in the clashes, which erupted after several dozen protesters attempted to break riot police lines, with some throwing bottles and stones at the officers. Police responded with pepper spray and batons in order to push back the angry youths.

Initially peaceful, the rally was held at the Brenner Pass border located on the Austria-Italian frontier on Sunday. Up to 1,500 attended the human rights event, according to various estimates.

Heute haben wir ein klares Zeichen gegen Abschottung gesetzt. Protect people, not borders! #Overthefortress#Brennerpic.twitter.com/5PuNmVpP09 — GRÜNE JUGEND (@gruene_jugend) April 3, 2016

The demonstrators could be seen lighting flares, throwing life-jackets at police, waving flags and carrying placards reading "Refugees Welcome! No more fortress Europe” and "No border in Brenner". Others were holding a “#Overthefortress” banner and mock-up tents in their hands.

A huge “Refugees Welcome to EU” could be seen on the ground, while another “Welcome” message was sprayed over a sign announcing a passageway to Austria.

Austria announced earlier it planned to strengthen border controls at Brenner to level off the number of incoming refugees. Vienna expressed concern that it could face an unexpected inflow of refugees coming through Italy, especially with the EU refugee deal with Turkey coming into effect on Monday.

On Saturday, Peter Doskozil, Austira’s Defence Minister said that Vienna would deploy troops at the border checkpoint.

READ MORE: Austria to deploy troops at Alpine border to stop refugees coming through Italy

“As the EU’s external borders are not yet effectively protected, Austria will soon ramp up strict border controls. That means massive border controls at the Brenner (Pass), and with soldiers,” Doskozil told the German daily Die Welt. He said that there were “three companies with 100 men each ready to deploy.”