"A big explosion hits a terrorist arms market in Mayadeen, killing 30 terrorists and wounding dozens of others," the television reported.
A rebel official from the town in Deir Ezzor province told AFP the blast killed at least 15 civilians in a street market.
He said a car bomb was detonated by the jihadist Islamic State of Iraq and the Levant (ISIL), the same group which has spearheaded an offensive in neighboring Iraq this week that has seen militants sweep down from second city Mosul towards Baghdad, AFP reported.