Authorities from Serbia and Bosnia have arrested 15 people implicated in a massacre committed during the Balkan War.
The wartime rivals cooperated to detain the suspects involved in the Strpci massacre of 27 February 1993, where 19 non-Serb men were taken from a train and murdered.
"We are now on the path to solve the murder that has been hidden for more than 20 years," Serbian war crimes prosecutor Bruno Vekaric told Associated Press. "We have to do it for the innocent victims."
The pre-dawn raids were carried out to capture five suspects in Serbia and 10 in Bosnia. Those arrested included the brother of a detained warlord, a former Bosnian Serb general and ex-militiamen.
"Many war criminals are still influential in business, politics, police and the army," said Bosnian State Prosecutor Goran Salihovic.
There was no immediate comment from the detained suspects or their lawyers.
The failure of authorities to investigate the massacre for twenty years has remained an emotional issue in Serbia.
The Balkan conflict in the 1990s, fought between Serbs and Croats, left more than 100,000 people dead and millions displaced.