As the diplomatic summit on the Syria crisis got underway in Switzerland on Wednesday, reports of the suspected “systematic killings” of 11,000 prisoners heightened the urgency of the proceedings.

International condemnation of the alleged mass-scale slaughter was underscored by three former prosecutors who presided over past cases in the former Yugoslavia and Sierra Leone.

The information that sparked this latest intervention came from a military policeman who was working secretly with a Syrian opposition group and has since fled the country. Here’s more from The Guardian’s story, which also provided the basis for Juan Cole’s recent column on the topic:

The three, former prosecutors at the criminal tribunals for the former Yugoslavia and Sierra Leone, examined thousands of Syrian government photographs and files recording deaths in the custody of regime security forces from March 2011 to last August.

Most of the victims were young men and many corpses were emaciated, bloodstained and bore signs of torture. Some had no eyes; others showed signs of strangulation or electrocution.

The UN and independent human rights groups have documented abuses by both Bashar al-Assad’s government and rebels, but experts say this evidence is more detailed and on a far larger scale than anything else that has yet emerged from the 34-month crisis.

— Posted by Donald Kaufman.