Updated at 11:20 a.m. ET

A U.S. Navy SEAL special operator was killed during an attack by ISIS fighters Tuesday in northern Iraq, Defense Department officials tell NPR's Tom Bowman.

"The sailor was helping advise Kurdish Peshmerga forces about 3 miles behind the front lines when Islamic State fighters broke through with what's been described as a complex attack involving car or truck bombs and then subsequent infantry-style raids," Tom reports. "The SEAL was killed in a firefight, the Defense officials said. The Pentagon is not sure how many ISIS fighters took part in this attack."

U.S. air support carried out nearly two dozen strikes by F-15s and drones to counter the attack, according to Defense officials. Speaking in Germany, Defense Secretary Ash Carter said the assault took place near the Iraqi city of Irbil.

The SEAL's name has not been released, pending family notification. The service member had been sent to Iraq on an "advise and assist" mission.

"Our thoughts and prayers are with the servicemember's family," Pentagon Press Secretary Peter Cook says in an official statement released this morning.

Kurdish news site Rudaw reports, "The incident happened in the vicinity of Tel Skuf, about 28 kilometers north of Mosul," adding that the service member's body was recovered by a U.S. helicopter. A Rudaw correspondent says nearly 400 ISIS fighters are believed to have been involved in the fight.

NPR's national security editor, Philip Ewing, tells us:

"At least two other American troops have been killed in action as part of the ISIS war, including a Marine artilleryman whose base came under attack in March and a Delta Force soldier last October in a raid that freed some Iraqi hostages."

Copyright 2016 NPR. To see more, visit http://www.npr.org/.