Story highlights U.S. thought it killed him months ago in Syria

Known as "Omar the Chechen," he was one of ISIS' top commanders

(CNN) The United States is trying to verify that an airstrike recently killed a high-ranking ISIS commander, and the Pentagon confirmed Wednesday that in a separate action it took out a commander of the Pakistani Taliban who was responsible for the deaths of more than 130 children.

U.S. warplanes targeted senior ISIS operative Omar al-Shishani in Iraq in the past few days, some four months after the coalition first thought it had killed him in Syria, according to two U.S. officials. The United States is still trying to confirm they got him this time, the U.S. officials said.

Al-Shishani, also known as "Omar the Chechen," was targeted by an airstrike near Qarayyah, Iraq, south of Mosul, the officials said. But they would not speak publicly until it's certain this time that he is dead. If he has been killed in Iraq, it's a sign that top ISIS operatives are still able to move around the region with some degree of freedom.

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ISIS appeared to confirm Wednesday that al-Shishani was killed. The group's media wing, Amaq, citing an unspecified "military source," said he was killed in Sharqat while fighting to defend Mosul. Sharqat is just south of Qarayyah, where the U.S. officials said he was killed.

The Amaq report did not say when or how al-Shishani was killed.