Eight former Serb policemen have gone on trial in Belgrade accused of murdering 48 civilians during the Kosovo war.
Prosecutors say the bodies of victims were taken to Serbia
The killings allegedly took place in 1999 after the victims were herded into a cafe in the village of Suva Reka.
All but one of the dead were members of the same family, including 14 children, a pregnant woman, and a 100-year-old.
Their bodies were among more than 800 discovered in a mass grave outside Belgrade in 2001.
The BBC's Nick Hawton in Belgrade said that the eight men on trial at Belgrade's high-security war crimes court included a former assistant commander of the elite gendarmerie unit, as well as a former police chief from Suva Reka.
Suva Reka is on the main road south of the Kosovo capital, Pristina, and was on the front line of fighting between Serbian forces and Kosovo Liberation Army rebels during the build-up to the 1999 war.
The massacre was one of the most notorious incidents of the Kosovo war, in which an estimated 10,500 Kosovan Albanians were killed.
It occurred the day after Nato forces began bombing Serbia in an attempt to force it to withdraw forces which had been taking part in attacks on Kosovan rebels and ethnic Albanian civilians.
The trial is the first linked to the mass grave at a police training camp at Batajnica, near the Serbian capital Belgrade.
The mass grave was uncovered following the fall of former Yugoslav President Slobodan Milosevic in 2001.