Story highlights The cell is comprised of chemical weapons specialists from Iraq and Syria

The new unit is being set up in an ISIS-controlled area in Syria within the Euphrates River Valley

(CNN) US intelligence believes ISIS is bringing together all of its experts on chemical weapons from Iraq and Syria into a new "chemical weapons cell," according to a US official.

The cell is comprised of chemical weapons specialists from Iraq and Syria who have not previously worked together, the official added. The new unit is being set up in an ISIS-controlled area in Syria within the Euphrates River Valley, between Mayadin, Syria and the town of al Qaim, just across the Iraqi border.

That location has sparked a good deal of interest on the part of US military intelligence. One US defense official told CNN that "thousands" of ISIS operatives and sympathizers may be in the area and that ISIS leader Abu Bakr al Baghdadi could also be in hiding somewhere nearby. The area is now considered the "de facto" capital of ISIS, with Raqqa under such military pressure from the coalition and local forces, the official said.

Coalition officials still stress that given its size and status, the capture of Raqqa is still considered to be an important military objective.

It is assessed that ISIS is consolidating its chemical weapons capabilities in order to boost its ability to defend its remaining strongholds.

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