Northwestern border crossing with Croatia briefly closed to prevent about 100 people from entering the European Union.

Bosnian border police have stopped about 100 refugees and migrants from reaching the border with Croatia, a member of the European Union, amid a rise in the influx of people heading through the Balkans towards Western Europe.

The group of people attempted on Monday to reach the border, but police reacted quickly by blocking the two roads that lead to the closed-down crossing, Al Jazeera’s Josip Saric, reporting from Velika Kladusa in northwestern Bosnia, said.

Croatia also mobilised police on its side of the border, according to Anel Ramic, interior minister of the Bosnian northwestern Unsko-Sanski canton.

“Croatia sealed its borders,” Ramic said at a news conference in the Bosnian town of Bihac.

The group had moved towards Croatia from the nearby town of Velika Kladusa. An estimated 3,000 refugees and migrants are currently spread across the area.

“Many have attempted to cross into Croatia and are turned back – sometimes, five, six or 10 times. But they don’t give up; they keep trying,” Al Jazeera’s Saric said.

He added that there is frustration among residents in the small town of Velika Kladusa as an estimated 50-70 migrants continue to arrive daily.

“Residents aren’t satisfied with today’s situation. They are demanding from authorities a higher number of special police – not traffic police who have been dealing with this – and they’re worried that these situations could happen again and could turn into something else.”

The International Red Cross says the number of people migrating through the Balkans is on the rise and that they are in dire need of basic humanitarian support.

Authorities in Bosnia have struggled with the influx of thousands of people from the Middle East, Africa and Asia as many head there to avoid more heavily guarded routes through the Balkans in their bid to reach the EU.

Peter Van der Auweraert, from the International Organization for Migration, tweeted that the attempted group crossing on Monday was a “very worrying development” that risked creating a backlash.

Van der Auweraert explained in a phone interview with The Associated Press that the migrant influx has already put pressure on post-war Bosnia and that any incidents could further strain the situation. Bosnians might start viewing migrants as “troublemakers” rather than people in need of help, he said.

#BREAKING @UNmigration #Bosnia #migrant protection team are witnessing group irregular border crossing attempt towards #Croatia in Velika Kladusha. Very worrying development that risks to create backlash that is not in interest of anyone. pic.twitter.com/jlrCH95MPt — Peter Van der Auweraert (@PeterAuweraert) June 18, 2018

Another video made by team @UNmigration #bosnia of #migrants #refugees walking to Velika Kladuša – Maljevac border crossing at 1pm this afternoon @IOM_ROVienna pic.twitter.com/b55PGow9H8 — Peter Van der Auweraert (@PeterAuweraert) June 18, 2018

2018 – a record year

The International Federation of Red Cross and Red Crescent Societies said on Monday that more than 5,600 migrants have reached Bosnia and Herzegovina so far this year, compared with only 754 in all of 2017.

The Red Cross also said that in Montenegro, 557 asylum requests were registered in May, the highest monthly figure in five years.

Simon Missiri, regional director for Europe, said his group’s Balkan offices need more assistance to help cope with the increased numbers.

Hundreds of thousands of people passed through the Balkans towards Europe at the peak of the mass migration in 2015. The flow eased for a while but has recently picked up pace with the new route through Bosnia.

Since peaking in 2015, the migrants’ use of the Balkan route towards Western Europe has been impaired in part by Hungary’s construction of razor-wire fences on its southern borders.