Thirteen Bosnian Serbs were arrested on Monday for allegedly participating in the massacre of Croats and Muslim Bosniaks in the early 1990s.
The arrests were made in and around the towns of Teslic and Doboj in Bosnia and Herzegovina.
As many as 40 Croats and Bosniaks were killed in the area during the Bosnian War, which tore the region apart between 1992 and 1995.
During the war, thousands of ethnic Croats and Bosniaks were rounded up and imprisoned by Bosnian Serb forces. Many were killed or tortured.
Tens of thousands of people were driven from their homes in ethnic cleansing campaigns conducted by all sides of the war.
Members of all three of Bosnia and Herzegovina's main ethnic groups engaged in ethnic cleansing, though Bosnian Serb forces committed the most widespread expulsions. As many as 100,000 people died in the war – most were civilians.
Torture, rape, forced deportations and executions were all used by ethnic fighters to divide up the country.
Monday's arrests are all suspected former Bosnian Serb soldiers and police officers, including alleged members of the defunct “Mice” military group.
The Mice have been accused of committing some of the most heinous war crimes of the conflict.
Prosecutors from the United Nations war crimes tribunal have been handed the case.