Interior ministers from six European Union (EU) countries said their nations had agreed to step up efforts to protect the bloc from illegal immigration and target groups of human smugglers that operate on its borders.

AP reported that the ministers from the V4 group of Central European nations — including the Czech Republic, Hungary, Poland and Slovakia — were joined by counterparts from Austria and Germany for a summit in the Hungarian city of Szeged, 8 kilometers from the bloc’s border with Serbia, from where migrants enter into Hungary via the so-called “Balkan migration route.”

This issue, they believe, requires a tougher response from countries in the region, explained the interior minister of the Czech Republic, Vit Rakusan, noting that migration is a “shared challenge” for Europe, but did not give details on how they would target smugglers.

Rakusan asserted that recent decisions by numerous European governments to reintroduce internal border checks within the visa-free Schengen zone were unsustainable, and that external border protection would be the focus of cooperation between the six governments going forward.

AP reported that, due to the proliferation of violence in northern Serbia in recent months, around 13 of the EU’s 27 member countries have reintroduced internal border checks with their neighbors.

Gun battles have become common along the border between Serbia and Hungary where migrants have gathered looking for ways to cross into the EU with the help of smugglers, reported AP.

At the summit on Monday, the six countries’ ministers agreed to discuss a common EU policy on immigration and asylum at a meeting in Brussels next week.

Hungarian Interior Minister Sandor Pinter said his country is not willing to compromise on a proposal that would distribute asylum seekers across the EU to reduce the burden on countries most affected by migration.