10 people have been arrested in Bosnia and a further five in Serbia following a joint investigation by the two countries. The suspects could face charges in connection with a mass murder during the Bosnian war.
The 15 suspects were arrested in connection with the kidnap and murder of at least 20 people during the 1992-1995 Bosnian War.
Former foes Bosnia and Serbia worked together on an unprecedented year-long investigation to arrest the suspected war criminals.
Bosnia's war crimes prosecutor said in a statement that the suspects arrested on Friday included "high ranking military officials from the Bosnian Serb army of the time as well as perpetrators involved in the brutal torture and execution of the victims."
Vladimir Vukcevic, Serbia's war crimes prosecutor told the news agency AFP that a new police team had been appointed in Serbia after the previous team were found to have tried to stall the case.
The attack took place on February 27, 1993, when a train travelling from Serbia to Montenegro was stopped by a Serbian paramilitary group as it passed through the Bosnian village of Strpci, close to the Serbian border.
Serbian paramilitary gunmen forced 20 of the passengers off the train, then took them to the nearby Bosnian town of Visegrad, where they were tortured and killed. Their bodies were thrown into the Drina river, the natural border between Bosnia and Serbia.
Three of the bodies were unearthed in 2010 when the Peruac lake was drained for repairs to a dam. The others have never been found.
Most of the victims of the Strpci attack were Muslim. During the Bosnian War, Serbia and Montenegro were still part of federal Yugoslavia. Serbian paramilitaries and the Bosnian Serb army (ethnic Serbs) were fighting Muslim Bosniaks and Catholic Croats to carve out an exclusively Serb statelet.
"We hope that this will bring closure to the Strpci case and give justice to the victims' families, who for 20 years have been looking for the remains of their loved ones and seeking justice," Vukcevik said.
Serbia's war crimes prosecutor, Vladimir Vukcevic
The 1993 attack in Strpci was blamed on a group headed by Serbian war criminal Milan Lukic, who was sentenced to life imprisonment in 2009 by the United Nationswar crimes tribunal for the Former Yugoslavia (ICTY).
Local media reported that Lukic's brother, Gojko Lukic, was among those arrested in Serbia on Friday.
Since the attack, evidence has emerged that senior political and security officials in Serbia knew that the Bosnian Serb army and Serbian paramilitary forces were planning to seize train passengers and possibly use them in exchange for prisoners or their dead comrades.
"It was a state-permitted crime," said Serbian human rights activist Natasha Kandic. She described the arrests as a "significant lesson that sooner or later the crime will be punished."
lvw/lw (Reuters, AFP)