(CNN) ISIS leader Abu Bakr al-Baghdadi is believed to have been killed in a raid conducted by the US military in northwest Syria on Saturday, according to a senior US defense official and a source with knowledge. The final confirmation is pending while DNA and biometric testing is conducted, both sources tell CNN.

The defense official said it appears that Baghdadi detonated a suicide vest during the raid.

The raid was carried out by special operations commandos, a source familiar with the operation told CNN.

The CIA assisted in locating the ISIS leader, the defense official said. Iraqi forces also gave "important information" in the operation, Maj. Gen. Tahseen al-Khafaji, a spokesperson for the Iraqi Joint Operations told CNN.

The Kurdish-lead Syrian Democratic Forces (SDF) tweeted that there was a "successful" joint operation with the US -- but did not specifically name what that operation was or give any further details.

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