A growing number of migrants are carving a new Balkan route through Bosnia to reach the European Union raising fears of a humanitarian and security crisis in the impoverished country.
In the tourist centre of Sarajevo, a park in front of the national library has been turned into a makeshift camp with several dozen tents.
Near the border with EU member Croatia, in the northwestern town of Bihac, migrants are squatting in a ruined university campus.
In Velika Kladusa, 40 kilometres (25 miles) further north, another improvised camp has been set up in a park.
Such places lack water and electricity, but many young men and also families with children, bed down there for several nights before trying to cross illegally into Croatia.
Many evidently succeed, with Bosnian Security Minister Dragan Mektic noting that out of 4,000 migrants who entered the country this year only one third remain.
The numbers are by no means comparable with the hundreds of thousands of people who took to the so-called Balkans route in 2015, before it was closed in March 2016. But that route avoided Bosnia's mountainous terrain.
But as summer approaches, Bosnia has increasingly become a stopover this year.
Some 1,200 migrants and refugees arrived in the past three weeks, according to Peter Van Der Auweraert, head of the international Organisation for Migrations (IOM) Bosnia mission.
Security minister Mektic reported between 80 and 150 daily entries in May.
The situation seems to have caught the authorities unprepared.
In Sarajevo, the arrivals are fed by volunteers and ordinary citizens.
The state "does not provide any supplies to them, neither food, nor medicaments, absolutely nothing," said Denisa Steffen, a Bosnian volunteer in her 40s.
"Failing to quickly accommodate these people, we risk creating a small humanitarian crisis in places where the migrants and the refugees are," said Van Der Auweraert.
- 'Try again and again' -
Bosnia has only one centre for asylum seekers that caters to about 150 people, located 40 kilometres from Sarajevo.
The authorities say they intend to open a second one with 300 beds near Mostar, well away from the migrant route.
Van Der Auweraert said several factors explain why Bosnia is attracting more and more migrants.
Travellers who have been blocked for months in Serbia are now "ready to take risks and go through more difficult terrain," he told AFP.
Iranians and North Africans in particular seem to have headed for Bosnia in recent weeks.
Also "now there are human traffickers who are active in Bosnia, and that's what attracts the migrants," Van Der Auweraert added.
"I tried to cross six times already and I reached the border between Croatia and Slovenia three times before being arrested by the police and returned to Bosnia," Islam, a 24-year-old Algerian who left his home three months ago, told AFP in Velika Kladusa.
Iranian Saeid Samadi, a mechanical engineer, was arrested twice between Bosnia and Croatia.
"But I will try again and again," the 32-year-old said after taking food distributed by the Red Cross in Bihac.
Council of Europe Human Rights Commissioner Dunja Mijatovic wrote to the Bosnian government this week criticising the "lack of a systematic response".
"I am concerned to learn that many refugees and migrants, including families with children, sleep rough on the streets, and have irregular access to food," Mijatovic wrote.
She said they also faced serious difficulties in accessing health care.
Fifteen migrants in Bihac have been diagnosed with scabies.
"That is not only a humanitarian problem, it also becomes a security problem," said the mayor of Bihac, Suhret Fazlic, denouncing government inertia.
Police have recorded several burglaries and petty crimes.
Prime Minister Denis Zvizdic vowed Monday to "settle the migrants in a human way".
But to do that Bosnia expects a "significant expert and technical, notably financial aid", from Europe and the United Nations, he added.
Europe has been coping with its worst migration crisis since World War II, but has sharply cut numbers since a 2015 peak when 1.2 million arrived in the block.
In fragile Bosnia, deeply divided along ethnic lines, the arrival issue has quickly become a political one.
The country is composed of two semi-independent entities, Serb-run Republika Srpska and the Federation of Croats and Muslims.
Half of the country's 3.5 million population are Muslims, but Bosnian Serb officials have warned that they will refuse to organise accommodation for the migrants, who often come from Muslim countries.
"We will find a way to defend ourselves from this invasion," said Milorad Dodik, President of the Bosnian Serbs' entity of Republika Srpska.