SARAJEVO (Reuters) - The International Federation of Red Cross and Red Crescent (IFRC) voiced concern on Thursday over worsening conditions for thousands of migrants stranded in Bosnia on their way to western Europe.

Bosnia was spared the migrant wave in 2015. But it now finds itself struggling to accommodate about 5,000 people who are trying to reach wealthier EU countries via neighboring Croatia, with many migrants reporting physical mistreatment by Croatian border guards as they try to cross.

Some 8,100 people from Asia and North Africa have entered Bosnia from Serbia and Montenegro since the beginning of 2018, including 3,000 over the past month, according to U.N. refugee agency UNHCR. Of the total number 3,000 managed to cross to Croatia.

With only two official asylum and refugee centers, the former Yugoslav republic is struggling to accommodate the migrants. New accommodation facilities are pending an agreement among Bosnia’s authorities.

Many migrants are staying in improvised shelters, tents and dilapidated building, lacking running water and toilets, especially in the north near the border with Croatia.

“The conditions close to the border are grossly inadequate and we’re concerned for people’s safety,” Nicole Robicheau, IFRC spokeswoman in Bihac, said on Thursday.

First aid teams from the local Red Cross in Bihac have been treating up to 70 people per day, mostly for injuries sustained while attempting to cross from Bosnia to Croatia.

“Many people whom we treat say they have been mistreated by the Croatian border guards when they try to cross the border,” Robicheau told Reuters.

“They come with a pain in their shoulder or with scars on their head. Some of them have tried to cross five or six times and have been turned back.”

Croatian authorities have denied reports of excessive force.

Authorities in Bihac and nearby Velika Kladusa with stretched resources and fearing health and security risks said they would stage a protest in front of the government building in Sarajevo next Thursday, unless proper accommodation for migrants is not provided.

“The situation in Bihac is alarming and it could get out of control any moment,” Bihac mayor Suhret Fazlic said.