U.S. Special Operations forces staged an overnight ground raid in Syria early Saturday, killing what the Obama administration said was a senior Islamic State official and capturing his wife.

Delta Force troops, flying from Iraq aboard Black Hawk helicopters and V-22 Ospreys, encountered almost immediate fire from militant forces when they touched down in al-Amr, near eastern Syrian oil fields that the Islamic State has tapped to generate income with black-market fuel sales.

In what a U.S. Defense official described as “close-quarters combat” against militants using women and children as human shields, about a dozen militants were killed. They included the target of what was originally designed as a capture operation, identified by the White House and the Pentagon as Abu Sayyaf, a Tunisian.

His wife, identified only as Umm Sayyaf, was said to have been captured and brought back to Iraq in one of the bullet-riddled U.S. aircraft that landed at dawn. Defense Secretary Ashton B. Carter said that no U.S. forces were killed or injured during the operation. No civilians were reported injured.

U.S. forces recovered laptops, cellphones, files and a number of archaeological artifacts and historic items, including an Assyrian Bible and antique coins, the Defense official said.

The soldiers also rescued a young woman, an Iraqi from the minority Yazidi sect, who was being held by the couple as a slave, according to statements issued by the White House and the Defense Department. Countless Yazidis have been executed or enslaved by the Islamic State as it has moved through their homeland in northern Iraq. Officials said they hope to reunite her with her family.

The raid was only the second time U.S. Special Operations forces are known to have operated on the ground in Syria, and the first “direct action” mission by U.S. forces there. Special operators conducted an unsuccessful mission last summer to rescue American hostages being held by the militants, who later executed them.

President Obama has said that U.S. forces, who have been conducting airstrikes against the Islamic State in Syria and neighboring Iraq, will not enter either of those countries in a ground combat role. Although several thousand U.S. troops are in Iraq training and assisting Iraqi forces, the administration has said there are none in Syria.

The raid in Syria came as Islamic State forces in Iraq tightened their grip on the city of Ramadi, in a significant setback to Iraq’s U.S.-backed government. Residents and police reached inside the city, the capital of Iraq’s largest province, said the militants were executing dozens of civilians and blowing up homes.

In Washington, the Defense official described Abu Sayyaf as “fairly high up” in the Islamic State hierarchy but not among the four most senior militants tracked by the United States. In addition to directing oil and gas operations in Syria, Abu Sayyaf was also “involved with the group’s military operation” and likely in contact with Islamic State leader Abu Bakr al-Baghdadi, the White House said.

Many of the U.S.-led airstrikes in Syria have targeted oil and gas refinery and storage sites, and the administration has said it has significantly reduced Islamic State revenue from that source. Al-Amr is located southeast of Deir al-Zour, the largest city in eastern Syria.

The U.S. expectation was that Abu Sayyaf’s removal will lead to further disruption in the Islamic State’s “revenue-generating network and command and control of ISIL operations,” according to a senior administration official. ISIL is another term for the Islamic State.

Beyond statements issued by the White House and Defense Department early Saturday, senior officials spoke on the condition of anonymity about still-secret details of the raid.

Officials said that the building targeted in the operation had been under surveillance for several weeks before the raid. The White House statement said that Obama authorized the operation “with full consent of Iraqi authorities” and upon “the unanimous recommendation of his national security team.”

Senior lawmakers, including the leaders of intelligence committees in the House and Senate, were briefed on the mission Friday and were to be given details of the operation in further briefings this week.

The attempt to capture Abu Sayyaf was made not only because of the positions he held but also to obtain information about the Islamic State and possible hostages who are still being held by the militants, officials said.

Although there are no public reports of Americans being held in Syria, the senior administration official said: “We are aware of reports that other U.S. citizens have gone missing in Syria. But due to privacy concerns, we have no further comment.”

Other officials said that the intelligence community and the FBI continue to gather information and evidence in connection with previous hostages.

The last known U.S. ground raid inside Syria took place in July, when Special Operations forces landed outside the north-central city of Raqqa, which serves as Islamic State headquarters in that country, to rescue journalists James Foley and Steven Sotloff. When they arrived, they found the hostages had been moved. Foley, Sotloff and several European hostages were subsequently beheaded by the militants, and an American woman held with them, Kayla Mueller, was also later killed.

The White House statement on the most recent raid said that U.S. forces were working “to determine an ultimate disposition” for Umm Sayyaf, who it said was currently being held in “U.S. military detention in Iraq.”

The Defense official said she was being debriefed and described her as a “player” in the Islamic State and an active participant in her husband’s activities. The senior administration official said that Umm Sayyaf was being debriefed “to obtain intelligence about ISIL operations” and “to determine any information she may have regarding hostages — including American citizens who were held by ISIL.”

For a video, go to bit.ly/AbuSayyafVideo

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