The United Nations says Syrian militants did not return the weapons, uniforms and cars taken from 45 Fijian peacekeepers who were released last week after two weeks of captivity on the Syrian-controlled side of the Golan Heights.

U.N. deputy spokesman Farhan Haq told reporters Wednesday that "the possession and use of U.N.-marked assets by non-U.N. people is of concern to the United Nations."

The Fijians were captured Aug. 28 by the al-Qaida-linked Nusra Front, who have been battling Syrian government forces in the contested buffer zone between Syria and Israel. The 1,200-strong U.N. force has increasingly been caught in the spillover from Syria's civil war.

The U.N. withdrew many other peacekeepers this past weekend. Haq said they left with all critical equipment including weapons, maps and data.