A member of the one of the Palestinian militant groups in Gaza admitted to Ynet on Thursday that the phosphorus used in the rockets fired on Israel Wednesday contained material gathered from shells Israel itself fired on Gaza during Operation Cast Lead.

"The phosphorus was taken from bombs Israel fired, that didn’t explode," he said.

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The source said that the Gaza groups were continuing their quest to enhance their offensive capabilities, especially regarding rocket range and explosive capabilities.

"This has nothing to do with the peace talks , but with our desire to improve ourselves."

Nine mortar shells were fired from northern Gaza at southern Israel on Wednesday, and according to police demolition experts, several of them contained phosphorous. It was the first time such munitions were used by any of the Gaza groups. Nevertheless, police officials said such rockets were equal to regular mortar shells, damage wise.

Israel came under harsh international criticism for using phosphorous shells during its January 2009 Gaza campaign. Jerusalem stated the material was used according to International Law, which grants the use of phosphorous shells in unpopulated areas.