Israel used depleted uranium shells in the alleged strike in Syria on Sunday, a senior Syrian military source told Russia Today on Monday.
"When the explosion happened it felt like an earthquake, then a giant golden mushroom of fire appeared. This tells us that Israel used depleted uranium shells," the source said.
Depleted uranium is a byproduct of the production of enriched uranium for use in nuclear reactors. It is 2.5 times as dense as steel, which allows it to penetrate heavy protection. The material is known to be toxic, but not dangerously radioactive.