Medical charity Doctors Without Borders (MSF) accused the Bulgarian, Croatian and Hungarian police of resorting to violence against migrants, notably children, in their bid to stop them from slipping into Europe, AFP reports.
"For the children and young people trying to leave Serbia today, violence is a constant and the overwhelming majority is perpetrated by EU member states border police," the head of MSF in Serbia, Stephane Moissaing, said in a statement.
"For more than a year our doctors and nurses have continued to hear the same, repetitive story of young people being beaten, humiliated, and attacked with dogs for desperately trying to continue their journeys," the statement said.
In the first six months of 2017, 92% of children and teenagers attending MSF mental health clinics and reporting physical violence named the Bulgarian, Hungarian and Croatian police or border authorities as the perpetrators, he said.
Nearly half of the children singled out Bulgarian authorities, the statement said.
MSF said it was disgraceful that EU member states were intentionally using violence to deter children and young people from seeking asylum in the bloc.
"It is causing serious damage, both physical and psychological, making them more vulnerable and pushing them back into the hands of the smugglers the EU and member states claim to be fighting," it said.
Hundreds of thousands of migrants travelling to western and northern Europe passed through the so-called Balkan route until it was shut down in 2016.
Several thousands of them got stuck in Serbia, but every day dozens try to continue on their journey.