Clutching prayer beads and a documented death threat from the Taliban, Mirwais joins a queue outside Kabul's passport office, potentially among a second wave of migrants attempting perilous journeys to Europe, inspired by images of refugees being welcomed.

Afghans are the second largest migrant group -- behind Syrians -– arriving in Europe, where authorities from the Mediterranean to the Baltic Sea are struggling to cope with the continent’s worst refugee crisis since World War II.

The prospect of a new tide of war refugees -- from Afghanistan to Iraq and North Africa -- poses a daunting challenge for EU policymakers already scrambling for a unified response to the overwhelming influx of people.

"The flood gates are open -– and this is our best chance to reach Europe," said 28-year-old Mirwais, a former translator at an American base in the volatile eastern province of Kunar.

Mirwais, who has been waiting for a US Special Immigrant Visa (SIV)since he complained of Taliban threats in 2012, has been captivated by television footage of refugees pouring into Europe.

In particular, it was the image of dozens of Germans holding up "Welcome Refugee" signs that prompted Mirwais, who goes by one name, to travel to Kabul to renew his passport.

His plan: if the SIV doesn't imminently materialise, he will pay one of the ubiquitous human smuggler networks flourishing in Afghanistan to undertake a dangerous voyage -- through Iran and onwards to Turkey and finally, Germany.

"I hear Syrian refugees are being given a priority in Germany," said Mirwais, the amber coloured tasbih -- prayer beads -- wrapped around his wrist, as he joined a queue snaking outside Kabul’s passport office.

"But I think Afghans have a good chance."

Mirwais is one of thousands of jobless Afghan civilians eager to find refuge in Western nations, fleeing decades of turmoil and war tearing their country apart.

The number of his countrymen seeking asylum in industrialised nations has now surpassed all previous years since 2001, with the UN refugee agency reporting a 65 percent surge in applications in 2014 over the previous year.

New figures from the agency show Afghans constitute 14 percent of the 381,412 people recorded as having arrived in Europe by sea so far this year, making them the second largest migrant group after Syrians.

- 'Inspired by images' -

"We can be sure that these same Afghans inspired by the TV images of those who have reached Europe have also seen photos or images of those who have died on their way there," said Richard Danziger, the country head of the International Organization for Migration (IOM).

"But the images and stories of successful migration projects always make more of a mark than those of failure," Danziger told AFP.

The serpentine lines outside Kabul's passport office are a sign of the gathering pace of the exodus from Afghanistan, where pessimism abounds about a deteriorating war and a slumping economy.

Former President Hamid Karzai on Wednesday joined a growing chorus of officials imploring Afghans to halt the flight.

"Dear young Afghans, stay in your country, build your homeland," he said. "The country is facing a hard time and it needs you to stay."

But such pleas fall on deaf ears.

"Telling people not to migrate doesn't work," said Danziger.

"The best the (Afghan government) can do is to reach out to those most likely to go and engage them in dialogue. In the longer term, of course, the answer is economic opportunities and security."

- 'Chop off your head' -

Four decades of war have brought endurance among Afghans, but the expanding conflict, the spectre of the spread of Islamic State, and growing economic distress have whipped up an undercurrent of hopelessness.

Many migrants are desperate to get into northern EU countries that have thrown open their doors, but between them lie several transit countries, some of which -- like Hungary -- are intent on keeping them out.

"Whether Germany or Austria welcome us or not, we have to go," said Haji Popal, a 65-year-old Afghan father of nine, planning a similar voyage to Europe.

"We'll go wherever we are welcome."

Meanwhile, Mirwais, heaving and sweating, waited patiently in the queue outside the passport office, where potential migrants start massing as early as 4.00 am.

Once a translator with the US army's Road Clearance Patrol unit, tasked with clearing improvised explosive devices, he said his life has been stuck in limbo since militant threats forced him to flee his home.

"The Americans shut down their base and left. We stayed behind to face death threats," he said.

Mirwais pulled out a chilling letter, purportedly from the Taliban, left on his front door one morning in 2012.

"We will chop off your head for working with foreign infidels," the letter said.