U.S. Special Operations forces killed a senior ISIS commander during a raid intended to capture him in eastern Syria overnight Friday to Saturday, U.S. Secretary of Defense Ash Carter said.

The ISIS commander, Abu Sayyaf, fought capture and was killed in the raid in al-Amr, he said in a statement.

Carter said he had ordered the raid at the direction of President Barack Obama. All the U.S. troops involved returned safely.

“Abu Sayyaf was involved in ISIL’s military operations and helped direct the terrorist organization’s illicit oil, gas, and financial operations as well,” he said.

His wife, an Iraqi named Umm Sayyaf, was captured and is currently in military detention in Iraq, National Security Council spokeswoman Bernadette Meehan said in a statement.

Umm Sayyaf “played an important role in ISIL’s terrorist activities, and may have been complicit in what appears to have been the enslavement of a young Yezidi woman rescued last night,” Carter said. ISIL is an alternative acronym for ISIS.

Umm Sayyaf is believed to have been involved in human trafficking and hostage taking.

About a dozen ISIS fighters were killed in the firefight at a residential building in Deir Ezzor, the sources said.

Abu Sayyaf is not a name familiar to many ISIS watchers.

But the fact that the United States clearly had him under close watch was ready to put its forces at risk by going deep into Syria to carry out the raid suggests they saw the target as very valuable.