Official: U.S. keeping ISIS kill list

One U.S. official said Baghdadi is well aware the U.S. is hunting him, so the belief is he is staying out of sight. It's been months since the last intelligence report about where Baghdadi is hiding, a senior U.S. official tells CNN. The U.S. believes Al Baghdadi knows warplanes are hunting him so he moves cautiously -- even as his influence has grown beyond Syria and Iraq, cnn reports.

The U.S. has already killed a dozen or so ISIS operatives on the list including an ISIS chemical weapons expert the senior official says. But others are added to the list as intelligence is gained about their role in ISIS. The official strongly emphasized that the command and control structure of ISIS remains murky and more intelligence is needed about the identity of top operatives.

ISIS executioners like so-called Jihadi John are still in the U.S. crosshairs -- but the list focuses on targeting those whose death would broadly hurt ISIS. The kill list may now expand as the U.S. struggles to understand an ISIS command structure made more confusing by the growth of ISIS adherents in Egypt, Yemen, Afghanistan, Pakistan and Libya. One analyst cautions those labeling themselves as ISIS all may have very different goals.

"We have to take each terrorist or cult organization in every country as a separate entity. We can't look at it as one big group. You may miss the most important targets when you are doing that," said Mark Hertling, CNN military analyst.

The execution of Egyptian Christians on the Libyan coastline underscores the targeting problem. The U.S. wants to identify the killers. But the broader worry is ISIS's position in Libya. It now has a stronghold in Derna and operates across Libyan coastal areas within reach of southern Europe via busy shipping lanes.

"It's very difficult to have the same kind of controls over people who might be getting on boats who might be working as stevedores or laborers on ships that are coming into European ports," Hertling said.