Civilian de-miners working in Libya have found another type of cluster bomb used last year during the war that overthrew Col. Muammar el-Qaddafi, according to the United Nations and Mines Advisory Group, or MAG, a nongovernment organization helping to clean up areas littered with mines and unexploded ordnance.

The cluster munitions, known as PTAB-2.5M’s, were found last month scattered in the desert near the eastern city of Ajdabiya.

A product of the Soviet Union, PTAB’s were first designed and fielded during Stalin’s time, and they have been used in several wars in the decades since. Each is a narrow bomblet shaped roughly like an aerosol spray can equipped with stabilizing fins at the tail. Each holds a shaped explosive charge designed to penetrate armor.