The highly dangerous radioactive material, stored at a US owned facility in Basra, Iraq, and stolen last November, sparked fears that could land in the hands of the ISIS. A box, the size of a laptop, contained Iridium 192, which uses gamma rays to determine flaws in oil and gas pipelines and the process is known as industrial gamma radiography.

“We are afraid the radioactive element will fall into the hands of Daesh (Isis),” the Independent quoted a senior security official, who wanted remain anonymous, as saying. “They could simply attach it to explosives to make a dirty bomb.”

A senior environment ministry official based in Basra told Reuters that 10g of Ir-192 contained in “capsules” was stolen from the oil depot.

According to the leaked environment ministry documents, dated November 30, reported “the theft of a highly dangerous radioactive source of Ir-192 with highly radioactive activity from a depot…in the Rafidhia area of Basra province.”

The International Atomic Energy Agency has classified the material as Category 2 radioactive, meaning it could be fatal to anybody in a close distance to it in just a few days or even hours. The U.S. State Department said that it is aware of the theft but confirmed it has no reports that ISIS, which has started using the chemical weapon, has acquired the material.

Last August, ISIS militants attacked Kurdish soldiers with mustard gas near Erbil, the capital of Kurd’s autonomous region in Iraq. This took around 35 Kurd soldiers ill.

Weatherford WFT.N, the US-based oilfield services company that owned the storage facility, issued a statement saying, “We do not own, operate or control sources or the bunker where the sources are stored.”

Large quantities of the radioactive material went missing previously as well from the US, UK and other countries, igniting fears that it could be used to make “dirty bombs.” This type of bombs is made by using a combination of nuclear materials with conventional explosives to contaminate a region with radiation.