It took seven years after Kosovo declared its independence from Serbia for Besim Aaliti to conclude that Europe’s newest state no longer offered him a future.

So Mr Aaliti, a bricklayer from the Kosovan village of Strubulovo, travelled through Serbia and Hungary to reach Germany, where he applied for asylum earlier this month.

He is one of tens of thousands who have left Kosovo in recent months, prompting fears in some European capitals that a mass exodus of migrants from one of the continent’s poorest countries could strain public services in destination countries and trigger a political backlash.

In Hungary, where most Kosovans first enter the EU, officials say they have received nearly 23,000 asylum requests in the past seven weeks, already surpassing the total for all of 2014.

“We are dealing with an extremely serious problem here and it’s a problem that’s beyond the scope of this government alone — it’s a problem for the whole EU,” said Zoltan Kovács, a Hungarian state secretary.

The vast majority of asylum-seekers disappear before their applications can be assessed, Hungarian authorities say, making their way to more prosperous countries such as Germany.

The scale of the influx from Kosovo, a small nation of 1.82m people, has surprised European policy makers otherwise focused on controlling immigration from conflicts flaring in Syria and north Africa. Kosovans accounted for 40 per cent of all illegal entries into Europe’s passport-free Schengen zone in December, according to the EU border agency Frontex.

Emigration is nothing new for Kosovans — nearly half of all households report a family member living abroad. Kosovo was wracked by the Balkan wars of the early 1990s and was administered by the UN for nearly a decade before finally declaring independence from Serbia in 2008. In spite of western aid, corruption continues to flourish and its citizens rank among Europe’s poorest.

Still, analysts are struggling to explain the current exodus. Some cite economic hardship — a draft study by the Group for Legal and Political Studies (GLPS), a Pristina-based think-tank, notes low incomes and youth unemployment at nearly 56 per cent. The European Commission has referred to a “criminal infiltration of the political, legal and economic systems”.

But others note that economic indicators have remained steady since 2008 and instead point to declining trust in the country’s unstable political structures. Residual ethnic tensions flared in January when members of the country’s ethnic Albanian majority protested against a newly formed government that includes Belgrade-backed ethnic Serb ministers.

“There were demonstrations and people were afraid, because perhaps a civil war is coming,” Mr Aaliti told the Financial Times at an emergency shelter in Berlin.

Another explanation is far more mundane: new passport rules. An EU-mandated change in border rules since 2012 has made it easier for migrants to enter Serbia using Kosovan identification documents.

The change was introduced as part of a Brussels-sponsored dialogue to improve relations between Kosovo and Serbia. But it has brought unforeseen consequences in the form of busloads of Kosovans leaving Pristina daily on the first stage of a journey to the EU.

The recent migrant surge is being supported by a sophisticated network of human traffickers, who send daily convoys of buses to towns such as Subotica, near the Serbia-Hungary border. From there, migrants travel by foot across Hungary’s porous frontier and into the EU. Waiting taxi drivers bring them to cities such as Vienna and Berlin, sometimes charging up to €3,000 for the ride.

“This is a major criminal enterprise,” says Fisnik Korenica, GLPS director. “Last year there were just one or two illegal routes across the Tisza river. Today there are dozens of illegal routes between Serbia and Hungary and yet for some reason, there are almost no indictments of traffickers.”

In Berlin, officials say minorities such as the Roma dominated asylum claims from Kosovo until recently. But now middle class Kosovans are also leaving in search of better prospects in western Europe.

At the shelter, Mehdi Krasniqi, a 47-year-old from the town of Vushtrri, describes Kosovo as a place where legitimate businesses are stifled. “There is corruption. I worked as a cook in a restaurant. The restaurant was burnt down because they didn’t give [protection] money,” he recalled.

There is little prospect of the latest arrivals being granted asylum in EU countries — less than 0.3 per cent of applications in Germany were approved last month. Two weeks ago, 30 rejected Kosovan asylum seekers were deported on a charter flight from Munich to Pristina.

Still, Vladimir Petronijevic, director of Group 484, a migration policy think-tank in Belgrade, says: “We know there is a significant number who make it into the EU without applying for asylum or getting apprehended.”

The surge of arrivals is triggering demands for a stronger response by authorities as public tolerance strains. In Germany, a new populist movement, Pegida, has harnessed public anger against immigration, drawing tens of thousands of supporters to marches in Dresden in recent months.

“There is certainly local opposition,” said Gerd Landsberg, managing director of the German Association of Towns and Municipalities, a lobby group, noting the burden on local schools and housing. “We always have to make clear why these [refugees] come, what has befallen these people.”

In Hungary, lawmakers last week convened a parliamentary debate on immigration, during which several participants linked increased migration to terrorism, arson and fraud. One border town mayor has demanded a fence be built to prevent Kosovans making their way through the forests and rivers on Hungary’s southern frontier. The border police have already installed heat-seeking cameras and are now trialling drones.

Western governments are also warning Kosovans against making the journey in the first place.

“Smugglers are lying,” read an advertisement in a Kosovan newspaper last week, paid for by the Austrian government. “You will not be granted asylum in Austria for economic reasons. Anyone staying illegally in Austria may be punished with a fine up to €7,500.”

But warnings and security measures will not solve the problem, says Mr Petronijevic: “The problems are bad governance and the lack of economic development in Kosovo. This is what the EU needs to address.”