Syrian authorities have preserved unspecified number of unidentified corpses of armed men killed in clashes with Syrian troops, pro-government al-Watan daily reported Wednesday.

The corpses haven't been claimed by any party so far, the paper said.

The men were killed after carrying out attacks against Syrian military forces, said the report, adding that some of the corpses were buried after the 90-day expiry legal limit.

No identity cards were found on those killed. All of the men were skin-headed and bearded, and were believed to be from different nationalities.

Local media recently reported that a number of foreign fighters, mostly affiliated with al-Qaida, has infiltrated into Syria to join fights against government troops.