A march to commemorate International Human Rights Day in Republika Srpska has been banned by police, prompting Amnesty International to urge the authorities to uphold the right to freedom of expression and assembly.
The event in the city of Prijedor was forbidden without any legal reason being given. Republika Srpska is one of the two entities that make up Bosnia and Herzegovina.
"The unacceptable decision to ban this peaceful march is the latest worrying example of the authorities' attempts to silence dissenting voices in Republika Srpska," said Lejla Hadzimesic, Amnesty International's Balkans researcher.
"The fact the police have not even given a valid reason for forbidding the peaceful march makes this appear even more sinister."
The march was supposed to bring attention to discrimination and numerous violations of human rights in Prijedor.
It was organised by a local Commemoration Committee, which is calling on authorities to investigate abuses of power and human rights violations committed in the area of and around Prijedor.
"Rather than trying to clamp down on activist groups in Prijedor, the authorities should be heeding their calls for justice," said Lejla Hadzimesic.
Last month, the UN Human Rights Committee criticized restrictions on freedom of expression and assembly in Prijedor.
In May, the town's mayor prohibited planned commemorations marking the 20th anniversary of mass atrocities that followed the Bosnia and Herzegovina conflict.
Prijedor residents were reportedly warned they would face prosecution if they used the term "genocide" to refer to the crimes committed during the war.
Two infamous concentration camps in the Prijedor region, Omarska and Keraterm, functioned throughout the Bosnia and Herzegovina conflict.
Many people were killed, tortured and sexually abused there, but most of those crimes have never been investigated and prosecuted by the local authorities.
Local NGOs say local police are responsible in many crimes committed at the camps, where more than 800 prisoners were reportedly killed or went missing.
Out of 28 processed war crimes cases from Prijedor municipality, 21 of the accused were police members, said the Commemoration Committee.
It added that nine other cases, some of which also involve police, are currently being processed in local courts.
Peaceful marches marking International Human Rights Day have been held in previous years in Prijedor without any problems.