Military intel identifies 'thickest' ISIS stronghold in Iraq

"That zone is where the enemy is thickest," Col. Steve Warren, chief spokesman for the coalition, told reporters Wednesday.

Two U.S. officials have told CNN they believe it's likely some senior ISIS operatives move through the area when they feel they can avoid U.S. surveillance.

"We've seen some of the leaders move their families, we believe, into Tal Afar as we've placed increased pressure on Mosul," Warren said.

He continued, "That zone is where the enemy is thickest. And personnel, leaders, equipment, information, money is moving, you know, back and forth within that corridor all the time, continuously. That's where they are."

U.S. warplanes strike targets in the area when they are able to find them, Warren said.

The Mosul-to-Tal Afar corridor also provides an access route to Raqqa in Syria.

Warren indicated Iraqi forces, backed up by U.S. air support, are beginning to try to isolate the area.

"You know, moving from the north, from the south, then moving really from the east, we're beginning to build the box around that enemy stronghold. And eventually, we'll begin to dismantle it," he said.

(СNN)