Nine people were injured after a van carrying 29 illegal migrants from Afghanistan and Iraq attempted to ram a police checkpoint on the border between Bosnia and Croatia.

The driver, thought to be Bosnian, had been discovered ferrying the migrants across the border from his own country, which is outside the European Union, into Croatia, which joined the bloc in 2013.

Croatian police set up a roadblock to stop the vehicle near the south-eastern town of Zadar, but the migrants decide they would attempt to ram through it rather than surrender, forcing officers to open fire, Business Insider reports.

“The driver did not stop after several warnings. He finally passed through a roadblock and drove towards the police. The police reaction was justified. They were forced to open fire because their lives were in danger,” said Zadar police chief Ranko Drazina.

Two migrants described as “children” were said to be in a “serious but stable” condition following the incident, with other injuries being less severe.

Croatia Warns 60,000 Migrants Ready to Break Through into European Union https://t.co/4PEoPl623t — Breitbart London (@BreitbartLondon) May 17, 2018

As the European Union’s newest member-state, Croatia does not yet enjoy full Free Movement rights with the rest of the bloc, and is still outside its borderless Schengen area.

Croatia has warned that the Balkan route for illegal migrants into Western and Northern Europe — brought partly under control after the EU agreed to pay the Turkish government billions of euros to slow the influx into Greece — could soon burst open again.

They believe people-smugglers are seeking to bring tens of thousands of illegal migrants still reaching Greece or already present there into their country through Albania, Montenegro, Serbia, and Bosnia.

Muslim-majority Albania is also an increasingly significant source of illegal migrants in its on right, along with neighbouring Kosovo.

Albanians and Kosovars can be harder to intercept than migrants entering the EU via Turkey or North Africa, as their home countries are already inside Europe proper.

Croatia President Accuses Merkel of Causing a Migration Car Crash as EU Leaders Meet http://t.co/5KoMCMxz1R pic.twitter.com/ybW51cwQmK — Breitbart London (@BreitbartLondon) September 22, 2015

Migrants had to adopt the complicated route through Croatia after Hungary’s conservative-nationalist government effectively sealed its frontiers by erecting a powerful border wall at the height of the migrant crisis.

The Croats initially scolded the Hungarians for their robust stance, saying they were “ready to accept and direct” migrants stopped at the Hungarian border, and added that “barbed wire in Europe in the 21st century is not an answer, it’s a threat.”

They climbed down from this position within days as migrants began pouring in, with then-prime minister Zoran Milanović telling Brussels: “We cannot register and accommodate these people any longer.”

“The European Union must know that Croatia will not become a migrant ‘hotspot’,” he said.

“We have hearts, but we also have heads.”

Follow Jack Montgomery on Twitter: @JackBMontgomery