The bodies of more than 50 people have been found on the shores of Lake Perucac on the border between Bosnia-Herzegovina and Serbia.
The BBC reports most of the bodies are believed to date from a massacre of Bosniaks (Bosnian Muslims) in the town of Visegrad during the 1992-95 Bosnian war.
More than 1000 people were killed by Serb forces in the town during "ethnic cleansing" in the spring of 1992.
Two Bosnian Serb commanders, Milan and Sredoje Lukic, were found guilty in 2009 of war crimes.
The BBC reports it is not the first time that grim discoveries have been found in the lake.
In 2001, a mass grave of 60 bodies was found, thought to be Kosovo Albanians killed during the 1999 conflict in Kosovo.