Syrian activists are reporting that at least 65 bodies of civilians have been found in a central town retaken by government forces from the Islamic State group. Most of the victims are believed to have been killed by IS.

The Britain-based Syrian Observatory for Human Rights says the number of those killed is Qaryatayn, in central Homs province, is likely to rise.

The Observatory says most of the dead were killed during the militant group's three-week seizure of the town. Syrian troops and allied fighters regained control of the town on Saturday.

The activist-run Palmyra Coordination Committee has published the names of the killed. It says at least 35 of the victims were found shot and their bodies dumped in a shaft.

IS has suffered major setbacks in recent months.