The Prosecutor's Office of Bosnia and Herzegovina says the remains are believed to be those of Bosnian and Croat victims from around the city of Prijedor, CNN reported Friday.
As of Thursday, 231 complete bodies had been removed from the site, said Boris Grubesic, a spokesman for the prosecutor's office. Body parts of 112 other people have also been exhumed.
More than 30 personal items have also been found.
Grubesic said the site, at Tomasica, is one of the largest mass graves found in Bosnia and Herzegovina since the end of the war in 1995.
Excavation of the grave began in September and is at least 33 feet deep.
Work at the site is expected to continue into next week.
Forensic analysis of the bones is being conducted at a center in Sanski Most to identify the remains.
Another grave site is being excavated at a garbage dump in Sarajevo. As many as 100 bodies may be buried there but 20 years of garbage must first be removed, the International Commission on Missing Persons said in a statement.