BEIRUT (AP) — U.N. observers have discovered 13 bound corpses in eastern Syria.

The latest killings apparently happened in Deir el-Zour province. The U.N. team says the victims appear to have been shot execution-style, with their hands tied behind their backs. Some appeared to have been shot in the head from a short distance.

The discovery follows last week's massacre in Houla (HOW'-lah) that left more than 100 people dead. Survivors blame gunmen allied with President Bashar Assad's regime for at least some of the carnage in Houla, while the government is blaming "armed terrorists."

The U.N.'s top human rights body has scheduled a special session for Friday to address the Houla massacre, which has drawn worldwide condemnation.

Meanwhile, violence continues elsewhere in Syria. Activists say government forces have been bombarding rebel-held areas in the same province where the Houla killings occurred. There's been no word on casualties.